/diy/ - Do It Yourself

>>2683331
Hello electronics anons. I want to build pic/link related because it's too expensive. Any tips? Specific resources I should look at? Or do you know of a Chinese version of this product?

Looking for something that can pulse up to ~a dozen or two Hz @ 10kV x 1mA (load will range from around 3kV - 10kV x 1mA)

https://www.xppower.com/portals/0/pdfs/SF_F_Series.pdf

>>2683358
moron

>>2683358
on the off chance this isn't for a taser, what do you want it for? what kind of output waveform are you looking for?

>>2683358
https://www.ebay.com/itm/314767331652

>>2683358
This one is listed as 400kV but it's closer to 10kV:
https://www.ebay.com/itm/314697094837

I need some help. I want to control my old bang & olufsen tv but i dont want to spend fortunes on a remote. Was looking into IR emitters until i found out b&o uses 455kHz for their remotes instead of using industry wide standard 32-38kHz. Anyone have any ideas or advice before I start this project?

>>2683331
I'm working through this book, about halfway through. It has you mechanically build out breadboard circuits that the author provides.
Am I wasting my time actually putting these things together? The only way I can imagine this part being beneficial is simply to improve your motor skills and troubleshooting skills if you fuck up.

>>2683484

according to some random internet dude, the Harmony H655 can be programmed to work with B&O teevees.
i have a dozen diff thrift-store Harmonys but not the 655.
if you gimme the model # of the tv i can see if Harmony has the codes available for download for other Harmony models.

>>2683499
>It has you mechanically build out breadboard circuits

us tinkerers never do it that way.
we just ask the Star-Trek replicator to do it for us.

>>2683499
It's the way to learn. Eventually you have ideas for your own circuits and then you begin by quickly breadboarding them.
Learning by practice is the best. It's obvious, right?
What is really the problem?

note this is for the PCB itself, I don't mean schematic sheets
I'm designing the board for a complex circuit in KiCad. But, the circuit is pretty much the same subcircuit copy/pasted over and over. Is there some way to only lay it out once, and then copy/paste it instead of having to laboriously re-do every single component for every single instance of the subcircuit?

>>2683518
Yes, there should be replicate layout plugin that allows you to duplicate layout of hierarchical sheets.

>>2683508
You're right, just need to slog through it. I'm sure the book will get me towards a decent level.
Also it's cool as fuck. Feels like playing with Legos again.
My ultimate goal is simply to design a coffee maker PCB.

>>2683501
godspeed to you anon, it's the beovision avant 28, but they all use the same beo4 remote. Pretty sure the type is 8111 but i can't get to the crt right now.

>>2683499
doesn't that book recommend putting BJTs in common-collector mode?

>>2683364
>moron
Yes?
>>2683370
>Le taser
If I wanted to make a taser there are plenty of anarchist cookbook style guides around that give way higher power outputs. No, I'm looking for something consumer electronics grade with relatively high fidelity and bandwith. You should have a closer look at those Xp Power units - they're much snazzier than a basic arc generator. My output waveform will be quite variable, but needs to be predictable based on the input signal. This is a complex circuit riddled with technical challenges, hence why I'm asking my question
>>2683478
Ok with a lot of work, this basic layout might be a jumping off point for what I actually want
>>2683481
>Input current 2-5A
Would it work if I run it at under an amp?

Apparently 2.6 X 3 = 10
According to chinks...
Also bastards have installed awful BMS that didn't balance shit, and now there is a big difference between cells (3.8 to 4.22V)
I've installed good BMS with balancing, but the question is, will balance fuck up this big, or i'm better off charging each cell individually?
And BMS is painfully slow at balancing too

>>2683643
I just measured like 650mA@3V (2 AA batteries).

>>2683651
880mA on second test with spark gap 0.5mm further apart

>>2683645
decided to charge each cell with a glidefish™ charger. I'm starting to suspect some cells are dead. Fuck me.

>>2683658
I think you have one or more bad connections either in the wiring or spot welds.

How come secondarys on microwave transformers will kill you, shouldnt the 1ghz frequency create skin effect like a tesla coil? what about a 25khz 10kva 30ma secondary

>>2683660
Spots look fine. Idk about balancing leads.
I blame manufacturer, they've installed a shitty BMS with no balancing, and since cells aren't LG/Panasonic/Sanyo, you need balancing as chink cells are all over the place when it comes to capacity, ESR and self-discharge.
>>2683663
Nerves can't process high frequency, so you're just being fried slowly to perfection.
Skin effect doesn't affect stuff that barely conducts electricity.

>>2683668
If you touched both sides of a high frequency high voltage secondary you be conducting that current though, would the current still pass through your organs or just skin tissue

>>2683663
>How come secondarys on microwave transformers will kill you
The transformer runs at 50/60Hz and steps up the voltage to ~2.2kV at about 1A continuous. That's 2200W AC.
>what about a 25khz 10kva 30ma secondary
I don't think you would feel 25kHz, but that's still 300W output and could burn tiny holes in your epidermis.

>>2683670
Exactly, this is what I meant.

can we get this kid an /ohm/ sponsorship so he can make bigger arcs in his room with more powerful equipment?
https://youtu.be/j6lq8Z8ZhjM?si=26X3aD5LSf-cU_pt

>>2683663
>shouldnt the 1ghz frequency create skin effect

the GHz signal is what comes out of the klystron, not the transformer.

>>2683499
Don’t buy or read anything using the term “maker” or its derivatives. It’s the hallmark of bullshit.

>>2683537
> coffee maker pcb
??? My coffee maker has made perfect coffee for 25 years, and I can guarantee you there is no PCB in there.

>>2683705
> ohm sponsorship
He’s already on track to win a darwin scholarship.

You chaps got any tube amp kits/resources?
Cursory search produced fully populated boards and premade enclosures where the hardest part is finding the right allen key to screw it all together. Don't mind if the pcb has all the surface-mounted shit baked on already, but something simple would be fine too.
>Looking for one of my analog module bookmarks ended up in a tangent looking at little tiny displays
>Didn't even find the bookmark I was looking for
damnit.

>>2683658
Welp. blew up the charger.Fuck.
Lii500 engineer. RIP, it cant handle 24V instead of 4.2V

>>2683651
>>2683652
Thanks, I'll look into it then

Check out my electronics review channel if you got a few minutes https://youtu.be/TzUaFmWAswo?si=lZXE7_Q5mgFPbueO

>>2683643
A ZVS transformer driver followed by a rectifier is going to be the simplest and cheapest thing like it, though the output regulation is minimal. What kind of voltage regulation do you need? What are you powering with it?

>>2683819
Problems:
>kinda amateurish demeanour (could be forgivable if the production quality was there)
>not sufficiently edited to trim out the fluff
>kinda not sufficiently researched or scripted beforehand
>vertical camera
>shitty camera
>shaky camera
>background noise
>kinda shitty mic
>poor working environment
Consider doing what bigclive does, having a phone/tablet as the camera mounted above a benchtop. An external microphone would be a benefit. There are things you could add in post, like a screenshot of the webpage you bought the neon sign transformer from, or the continuous display from a power meter, be it from a different camera or just a zoomed section of the current camera. A quick description of the MOT-based supply would also be nice.

What’s the best way to charge NiCd with the power supply? The ol’ Google is giving me varying answers. This pack probably hasn’t been charged in years fwiw.

>>2683499
Tilers tile; plumbers plumb; welders weld.
Electronics hobbyists mechanically build out breadboard circuits that the author provides, and then some.

>>2683893
>What’s the best way to charge NiCd with the power supply?

The best way is to not. End-of-charge state for NiCd/NiMH cells is determined by a slight dip in voltage. A simple CC/CV power supply has no way of detecting this, and will very quickly trash the cells.

>>2683909
Gay.

The graph showed a big temp increase too above like 80%, maybe I can wait til it’s nice and toasty.

>>2683893
Float it up to capacity at 1/40C over two days.
>This pack probably hasn’t been charged in years fwiw
It'll need a few full cycles to recondition; Expect it to underperform for the first two or three, and also to have lost a little headroom over the years.
>>2683909 Is somewhat correct, but has apparently never heard of a timer plug. Gay indeed. Overcharge damage is a product of charge rate and time. Keep the charge current below 1/20 capacity and the period > day, and you'll be fine.
>>2683911
What graph? Don't cook your cells.

>>2683909
I wonder what kind of temp sensors the Ridgid NiCd batteries had in em, maybe I can trick this charger into doing the Ryobi battery.

>>2683913
>What graph?

It’s an old NiCd Ryobi pack that was bound for the trash so idc if I wreck it in the process. I’d rather not destroy a charger though.

>>2683835
>ZVS transformer followed by a rectifier
The thing is going to be hooked up to a 1-2k mAh battery. Surely I don't have to screw around with DC->AC->DC? The off-the-shelf one uses a DC oscillator into a transformer
>What kind of voltage regulation do you need?
I don't need the voltage to be terribly stable. Pretty much the most rudimentary solution will do.
>What are you powering with it?
A soft actuator. I have electrodes sandwiched around a liquid dielectric enclosed in a non-extensible membrane. The high voltage induces a Maxwell stress which compresses the fluid when the electrodes are drawn together.

>>2683920
>Surely I don't have to screw around with DC->AC->DC
There's literally no other practical method of conversion, unless you count rotary converters.
>The off-the-shelf one uses a DC oscillator into a transformer
Oscillating DC is called AC. In this case, the datasheet calls it "a qμasi-sinewave oscillator", not sure what the µ is doing there. That quasi-sinewave is very similar to the sine wave coming out of the wall (i.e. it's AC), the only difference being there are gaps between the pulses. That's how it will be regulating the output voltage; the converter performs pulse-density-modulation in response to the feedback voltage. The quasi-sinewave is fed through a transformer to multiply the amplitude (transformers only work on AC), after which it's rectified and filtered with diodes and capacitors. This kind of sine-like oscillator (quasi-resonant is the correct term) lacks the sharp edges of a traditional switching converter (e.g. flyback) and as a result it's a lot less electrically noisy.

A simple ZVS circuit is very similar, just it doesn't have the quasi-part for regulation. Generally the output voltage is like k*N*Vin, where N is the turns ratio and k is some constant. I think, it might drop somewhat under load. Find a transformer with the right turns ratio N, or wind your own. ZVS circuits do need a centre-tap on their primary. 20kV silicon-stack diodes aren't that uncommon, I bough a dozen from aliexpress for like $5. Similar story for the caps.

You may also be able to find a dedicated IC that performs a ZVS, ZCS, or otherwise quasi-resonant conversion method. Otherwise there's nothing stopping you from making a forward converter using a TL494 or similar, which actually will have feedback. But both options will be more complicated (albeit easier to adjust) than the ZVS circuit.

I'm making a timed light that goes PIR input on timer pot-adjustable PWM MOS-driven LED.
Is there a reason not to use an op-amp configured as an astable multivibrator (pic rel) for my gate PWM signal instead of a 555?
The op-amp seems like a better option. Since there are two op-amps in a DIP-8 LM358, the second can be configured with some >megaohm resistors and an electrolytic cap as an (albeit imprecise) monostable vibrator for the timing function.

>>2683999
> reason not to use op-amp osc?
No good reason.
Lots of early computers used random oscillators made from leftovers or single transistors, or a couple of extra NAND gates.
Watch your current draw though, if it’s battery powered.
If you use a 555 you’d probably want the CMOS version.

>>2683999
>Is there a reason not to use an op-amp

the 555 has a reset pin, so you can turn the PWM on/off from the PIR without any additional circuitry.
also, op-amps are always fiddly, whereas the 555 is infinitely reliable.
even more reliable than mom.

>>2684007

...and the 555 can do 300mA vs 10mA for the op-amp.

>>2683999
Use a comparator instead of an op-amp, they're actually designed to be used with positive feedback so the output slew rate and voltage range is better. Generally higher current sinking too, though you often need a pullup.

If you do use a 555 timer, the normal NE555's quiescent current and output voltage range is pretty shit sitting 1.5V or more below the positive rail. That said, if you go for a CMOS 555, its output current sinking is a fair bit worse, and the output still sits half a volt or more below the positive rail. No clue how they got such a shitty part with CMOS.

>>2684007
>you can turn the PWM on/off from the PIR without any additional circuitry
The module's output has a set 8 second pull-up period, but I'd like a minute or more. Changing the module would require some very fine SMD reworking that is beyond both my dexterity and equipment.
>>2684112
>Use a comparator instead of an op-amp
The 358 is cheap and readily-available from a retailer down the road. It's a bit of an 'every problem looks like a nail' type of thing. Thanks for the rundown on comparators still.
>CMOS 555
>the output still sits half a volt or more below the positive rail
That's weird. I've heard their switching speed knocks the socks off the BJT variants though.
>If you do use a 555 timer, the normal NE555's quiescent current and output voltage range is pretty shit sitting 1.5V or more below the positive rail
Shouldn't be
>>2684008
>...and the 555 can do 300mA vs 10mA for the op-amp.
The MOS gate is only half a nanofarad. If my oscillator can switch its 10nF feedback cap at a kilohertz, then I think it'll toggle the measly gate capacitance just fine.

Help desk question – today an LED bulb in a regular 120v ceiling socket started flickering and then shut off. I almost wasn’t sure it happened/that the light had been on (dim bulb and around noon) so I reflexively jiggled the light switch, bulb came back on and did the same thing again a few minutes later. What’s causing this? Am I going to burn the place down if I keep using this? Is it the bulb/driver or the building wiring?

>>2684140
It's the board that drives the LED.

>>2684140
Swap it with another bulb to see if it's the socket or the bulb. Probably the bulb, but sometimes the contacts of a bulb get bent, and with the thermal expansion from running the bulb for a few minutes they can go open-circuit. Of course, heating up can also cause the LED bulb's board to trigger an overtemp condition and limit power, maybe the thermal paste has just gone shit.

>>2684141
>>2684142

Thanks, I figured but wanted to make sure it was safe (unless I’m misunderstanding what’s going on with open circuit)

>>2684138
>has a set 8 second pull-up period, but I'd like a minute or more.

no need to modify the PIR, just use a couple of schmitt gates to stretch the pulse.
a 555 monostable can do the same job.
even an op-amp can do it, if you have a hard-on for analog.

>>2684154
> more chips
The guy has the extra op-amp, any designer would just be efficient and use it.

> zoomer inb4
Just use an arduino and import some timer libraries

>>2683663
>How come secondarys on microwave transformers will kill you, shouldnt the 1ghz frequency create skin effect like a tesla coil?
2 reasons. First of all, they don't operate at 1 ghz, you might be confusing the transformer with the magnetron. Second, since the secondary is isolated from the primary, if you accidentally short the secondary through your body, a cfgi outlet won't protect you since there is no loss of current in the primary live and neutral wires. This means if you get zapped, you're cooked until the circuit breaker pops, which might or might not. At such high level powers, what kills you is not really the electricity stopping your heart anymore but the electricity cooking your body. Think of it similar to the electric chair and how some people would be cooked alive in it.

Whose dick do I have to suck to stop these 'convergence failed' errors?

Oh, I just realised that putting a hall sensor between the permanent magnets of a brushed DC motor's stator won't give a good speed signal; the rotor will always be putting out the same magnetic field polarity at that position, the magnetic field does not effectively rotate. It looks like there probably are some locations within the motor that I can get a solid speed reading from (since it's not sinusoidally driven), but I wouldn't easily be able to fix the hall sensor there like I can between the magnets. Also it gets switching noise. Guess I'll JB weld a pair of small magnets on the outside and hold a hall sensor to that. Optical is probably too much of a pain to get working without good baffles, which would be bulkier.

>testing motor
>now have speed measurement sorted
>still don't have current measurement
>assume current won't spike so long as i increase the duty-cycle steadily and have no mechanical load
>write code to steadily increase speed, and to cut the power if the hall sensor stops picking up a signal
>get up to 5100RPM
>kinda shaky but feels fine
>shut it down by pulling hall sensor out of the way
>motor brakes suddenly using the low-side MOSFET as a freewheel diode
>sudden torque spike
>10A psu just stops outputting any voltage
oh shit

it started again at least, but i should add a soft-stop as well as this soft-start.

>>2684633
The body diode is a mfg artifact, not a “free diode”
It’s also not a schottky diode, which is probably what you want as a flyback.
Start-up diagnostics should test to ensure the flyback diode is still working. It can be incorportated into the slow-start/stop.

>>2684646
>It’s also not a schottky diode, which is probably what you want as a flyback
Synchronous diodes are even better.
The brushed motor is in parallel with the low-side FET of a half-bridge. The half-bridge is either pulling low or high, one FET is always on. So during the "off-time" of the PWM, and when I tell it to shut off, current is cycling through the motor with the bottom FET acting like a synchronous freewheeling diode. Basically I'm shorting the motor out.
Even if it was a normal freewheel diode, it would barely give more effective electrical resistance than the FET, both would cause the motor to stop pretty quickly.

Also I don't call it a flyback diode, because flyback converters don't use a diode in parallel with any magnetic element. Such a diode would prevent the boost converter style voltage spike. It's a misnomer. I would suggest you do the same.

>>2684652
> freeloading diode
I make all my schematics using electron flow instead of conventional current flow because electrons are negative, not “positive” … it’s a misnomer. I suggest you do the same.

>>2684633
Yahoo, it's reliably working up to 18353RPM at maximum duty-cycle, which is right about this motor's purported maximum speed. I get the feeling this spin-coater is going to kill me. But now I really do need to implement some sort of current measurement, along with a manual control scheme. The ADC isn't working properly at the moment, definitely a brain problem since it works when I use the tarduino command but not when I access the register directly.

>>2683600
He explains the difference between the 2 but doesn't offer a blanket recommendation.
>>2683720
Probably true. Surprisingly this book was decent but it's a only starting point. I'm on AoE now and it's 10x higher level. Difficult as a beginner but the value on each page is huge.

Can a two-input latch be configured into an astable multivibrator?

>>2683499
yes, no, maybe, i don't know
rather than blindly making junk circuits, why not make something you can actually use? guitar effects, synthesizer modules, test equipment jigs give tons of opportunities to make useful shit, even at a beginner level

>>2684836
no

how hard is it to actually solder a 2x2mm chip to a circuit board using a solder paste without a stencil in a home oven?

>>2684858
If it were that easy then all the girls would be doing it.

>>2684842
thx

>>2684858
pretty easy. wick away the factory balls.
make leaded or low melt new balls using iron.
stick to pcb with flux put in oven.

>>2683331
Electronics bros, need a multimeter for my nephew (18yo). Level is higher than high school but lower than university.
Is pic relevant still relevant?
What are the current value kings?
>Budget is $50.
>Will mostly be used at low voltages (<=24)
>should be able to handle measuring AC mains (~240V) for a few seconds w/o frying
So far I know about:
>aneng q10
>aneng 8008
>aneng 8009
Which is best? How'd you sort them? Any other options to consider?

>>2684878
I got a an870 but I kinda wish I paid 2x more for a LCD display and a oscilloscope.
the specs on the scope about what you expect for a $40 DSO (and the specs are worse!), but the I am jealous of the display, and 18650.
https://www.youtube.com/watch?v=aUU-PGUnd0E
Technically, because you are measuring mains, you should just get a clamp meter because the best way to measure current in mains is with a clamp.
The only problem with clamps is that the specs for the probes are probably not going to be that great with measuring voltage at the low end, because clamps are HVAC / electrical / etc and they they don't really care about tiny voltages.
The an870 technically has better ranges than the ZT-702S and clamp meter, and many multimeters actually use the same chip as the an870 (like the AN8008 or kaiweets kn601, etc) but they can get different specs because they are wired differently.
People like the an870 / kaiweets km601 because it has 4 ports instead of 3.
Technically the best multimeters are around $120, and offer nice features you expect from oscilloscopes like high sample rates for finding peak voltages, etc.
Personally you shouldn't be mediating what he needs, he should be doing this research himself.
Technically if he doesn't know why he needs a multimeter, what specs they need, you could get a $5 meter and it would do 90% of the job (or a $15 clamp meter).
The used market may also be worth checking, maybe you can find a clamp meter that can measure DC for cheap (DC meters tend to be pretty expensive, most clamps only support AC).

>>2684912
*technically clamps are very inaccurate, and physically cannot measure low currents.
A dc clamp sounds awsome because you never need to cut wires to measure currents, but that's not how it works. A dc clamp would only be useful for measuring high currents, like a car battery or solar panels.
unrelated: technically you can measure DC current using an oscilloscope (like the one in the ZT-702S), and you can DIY the clamp yourself. But you also need a bench power supply (like a $30 riden dc to dc + AC to DC supply like a laptop charger) to test it.
https://www.youtube.com/watch?v=ohQF79cMODw
Also this is way out your budget, but I feel like I should mention the scope in the ZT-702S multimeter really sucks, and it's sad that if you spend 2x more on a HDS2202s, you can get a portable 200mhz scope with 2 probes (2 probes is much more useful than 1 probe because you can capture a waveform of a different part of the circuit using the other probe as the trigger) + you get a signal generator which can help with finding problems with wires.
BUT it's not a multimeter, it's only a scope. It would be a pain to use as a multimeter.

Any ideas how they do 5V regulator stuff?
Simplest solution probably is just having high value resistor on bypass/drain pin and feed into zener.

But drain pin probably has low resistance to high voltage, so I suspect that 5V regulator is current mirrors with some high-voltage transistors?

>>2684836
A two-input latch? Depends on the latch. You can if:
>it's an SR latch with both a Q and ~Q output
>it's a JK latch regardless of output
Not sure about D latches. Same should apply to flip-flops.

Note that none of these topologies intrinsically have schmitt inputs, so you're technically better using a comparator IC for this. That or a schmitt inverter, or a latch made from schmitt NAND or NOR gates.

>>2684858
Temperature control is going to be your biggest hurdle. Keeping the temperature high for a short enough time to not get outside the recommended reflow area basically necessitates a half-decent temperature control loop. Use a PID controller, or at the very least slap a thermocouple on the board and adjust the oven power manually and do a few test runs to make sure you don't overshoot.

>>2684878
The 8009 is just a better 8008. The Q10 looks like it's probably better, but I'd look for reviews and comparisons first. Also consider the Fluke 101. It's a name-brand tool with inferior specs (no current mode), but it may well be good enough.

>>2684934
It's almost certainly a pass-regulator, not a shunt regulator. The simplest method is an NPN voltage follower after a higher impedance reference diode, though it's most likely that they use something approximating an op-amp to get a solid output voltage via feedback. This is frequently just an NPN transistor, but for low dropout it's common to use a PNP transistor or even a P-channel MOSFET. Check the datasheet to see how close to 5V you can get the drain voltage before it stops working. These low dropout topologies are less stable and usually require an external bypass capacitor, which we see here, though of course the cap may also be buffering against ripple for when the drain is pulled low. It also needs to be of a topology that can handle negative voltages across it for the aforementioned drain being pulled low, though this can be achieved simply by using a series diode.

Could I make a battery for an older phone with USB-C Interface that can charge while the thing is on? New work wants me to bring my own phone so I'll dust of my old shark fin but the battery and interface sucks

>>2685126
Do you mean you charge this battery with a USB C port? Do you mean this battery is built into the older phone? If so it's possible, but not straightforward. The lithium charge circuit is relatively straightforward, rather the difficult parts will be the output interface and mechanical design.

>>2684912
I have one of these cheap portable oscilloscopes. Was like $100 and very nice. Zeeweii/SigPeak DSO2512G.
>>2684978
Needs to just be decent and cover the usual range of features, rather than good but less features.
This is for a person who has no multimeter at all, or experience using one. They're also fresh from high school.
I'll now investigate an8009 vs q10.
I also heard about a cm81 elsewhere.
Will probably get one of these multimeters + a small kit, and give them one of my breadboards (got a bunch unopened).

>>2685152
Get him a meter where the fuses are cheap and easy to replace. And some spare fuses for it. Accidentally leaving your meter with probes in the current pins is too easy, at least for meters that don't have the feature where they alert you when they're set to a non-current mode when the probe is in a current socket. Some nice Brymen meters have that probe alert feature, check if any of your potential meters have that.

Also see the eevblog dmm spreadsheet.

>>2684878
>>2684912
>>2684978
>>2685183
Ended up with an8009 + a breadboard kit.
Had to order on Amazon because it's needed by next week, else I would have gone with q10 or fluke 15b+ or 17b+ from aliexpress.
Amazon had q10, but it was basically 2x an8009, which itself is overpriced respective to aliexpress.
I'll also throw in a devboard from my collection. I got a shitton of different chips. I'll pick among the ones I have many of.
I think he's going to be very happy with this. If anything, it's gonna be overkill.

What would happen if i removed removed the zener diode from my laptop charger circuit? How will the output behave and can it fry the entire thing?
I don't know much about electronics

>>2685209
>can it fry the entire thing?

possible.
zeners are use in 2 main ways.
one is to establish a reference voltage for the output.
if you remove that, you'll get over-voltage to the circuit, and things can burn.
the other way is to cut off the occasional voltage spikes from lightening, or whatever.
if you remove it, likely nothing will happen.

>>2685239

...but, generally speaking, a zener should be considered a crucial component, not to be messed with.

>if you remove that, you'll get over-voltage to the circuit, and things can burn.
That's what i have been afraid off. I am trying to increase the amperage on the output, Mot much maybe one or two amps more, I can solder but i am short on components, is there a way to "overclock" it by removing something instead of adding more details?

>>2685256
>is there a way to "overclock" it by removing something instead of adding more details?

nope.
power supplies, like most everything else, are NOT designed with overhead in mind.
the major goal is always low-cost. so, there's no unused capabilities.
to increase current, you can (1) get a more powerful unit, or (2) carefully design a parallel supply to provide the extra needed amps.

Please help a simpleton with a basic question:
I have a Moroccan immigrant coming to live with me
I want to house him in my toolshed
My toolshed is powered by a 10-gauge wire plugged into a normal outlet on my porch
Breaker for said outlet is labeled 20 SWD, which I'm guessing means 20 amps
The wire to the toolshed is 100 feet long. I live at 9000 feet in Colorado so it gets cold, very cold. I understand that can affect amperage.

My question is, what kinds of things will my immigrant be able to run in the toolshed? If he has a tiny space heater, a lightbulb, and a phone charger going all at once will he burn down my home?

>>2684978
>It's almost certainly a pass-regulator, not a shunt regulator.
Will look into it.
Trying to see how offline switchers can self-power from 500+ VDC rail.

Old chips seem to mostly utilize high value resistors and zeners for self powering, newer designs are a bit more sophisticated it seems.

>>2685256
You likely can't increase output current. Power supplies are designed and specced for maximum output power, there is some bare minimum overhead for tolerances but that's it. If you need more current but not voltage, you can try using buck converter to reduce voltage but increase current.

>>2685342
>If he has a tiny space heater, a lightbulb, and a phone charger going all at once will he burn down my home?
If he has to pay the electricity for all that then yes.
Solution is very simple: don't house illegal aliens.

>>2685381
I don't think anon was serious, anon.
>>2685342
I don't think you're serious, anon. Electric blankets would be better anyway.

>>2685340
>to increase current, you can (1) get a more powerful unit
no i can't. i live in the middle of a desert and packages arrive after three weeks miniumum, if i am lucky.
the thing i am working on will become irrelevant before the details manage to arrive.
>(2) carefully design a parallel supply to provide the extra needed amps.
i know that you can chain them like batteries but the fact that my place has electricity at all is already hard to imagine, i lack everything.
no spare DC sources.
>you can try using buck converter to reduce voltage but increase current.
one of those things could solve all my problems for sure.
but i doubt that i can make one myself.
well i will survive without those 2 amps
thanks for the help

>>2685342
He cold improves the situation. Keeps wires cool.
Lightbulb and charger are negligible compared to the space heater, which is going to be over 1000 W more than likely.
10 awg 20 amp breaker. Probably fine, you could put another 15 amp breaker in-line somewhere if you’re worried about it.
You can always test it with some test loads, I use one a couple of space heaters to do my testing.

just realised that my op has been immortalised in the sticky
i also just realised that there's an erroneous > in the lithium battery link
this feels like a gsnk gag

>>2685343
>offline
they use zeners more often yes, but i think they always have to be external due to the heat production. maybe it's an internal zener with a really large value resistor that takes some time to charge up the capacitor, before it gets powered from an auxiliary winding? even a pass regulator is going to produce too much heat just from a milliamp, you can only drop the quiescent current of a switching converter by so much.

>>2685146
The entire battery is the backside of the phone. You click it into place

Is it possible to make your own SSD like device? People always say firmware is secret on storage devices, so couldn't I make an open source hardware storage? Is there anything like that? I've seen people make their own cpus and computers so surely someone has made storage devices?

What in Samhain happened to this Antarctican underwater PCB weaving board?

I'm working on this three phase motor starter and after about 5 minutes the coil goes open. It doesn't even feel hot. Is it typical for more than wire to be inside these? Like a variable resistor or something?

After about 10 minutes it returns to normal.

>>2685639
I guess, have a look at what flash ICs and FeRAM ICs cost per MB.

>>2685675
>Like a variable resistor or something?

likely a self-resetting thermal fuse.
if the thing is not actually hot, the fuse may be at end-of-life.

>>2685697
Yeah, the fuse is not designed to be tripped all the time. Approximately once, in fact.

>>2684705
>18353RPM
Did I read that correctly? That's a lot of energy. Don't forget your safety goggles.

>>2685126
I'm tired of employers who expect employees to BYOD and/or require them to install software on personal devices. If it is a requirement for work, you provide the preconfigured hardware and necessary software.

>>2685763
>Did I read that correctly?
Yeah 18 thousand rpm, or 300 oscillations per second
>That's a lot of energy.
At the moment it's just a shaft and nothing else spinning, but once I add the spin-coater's 4-jaw chuck on it (which is made from a cross of threaded rod), the moment of inertia will be an order of magnitude higher. I don't plan on taking it up to 18k rpm if I don't need to, if only because that would make balancing a very stringent requirement. And with the extra momentum it will spike current too high if I try to accelerate it too quickly. The scary thing is that I'll need to basically be next to the thing while it spins, in order to add the liquid atop it. So it's less the eyes and more the torso that's at risk, though safety glasses will be worn. I'll calculate the amount of energy for my planned rotation rate and figure out how much plywood or whatever I need to protect against my makeshift shuriken. I'm guessing like 20mm of wood, plus some sheet metal.

The other thing I need to consider is the control mechanism. I'm thinking of a spring-loaded slide-pot, though a capacitive PCB slider would be more reliable. Importantly, the thing needs to slow down once my hand has been removed, but not so rapidly to result in current spikes. Actually maybe braking current doesn't matter, since it isn't going back into the rails, and my FETs are rated at like 70A continuous.

>>2685784
I will pray for you.

How do I measure electromagnetic radiation? Someone moved into the apartment above me and my Windows bluetooth shows at least EIGHT Philips hue bulbs. I see two new Wi-Fi networks, each with separate 2.4 GHz and 5 GHz access points. He's the ultimate consumer. Any ideas how to make sense of what he brought into the house? I thought about measuring EMR? How do I go about that? I already called police and explained the situation two weeks ago and while they said they're going to looking into it they're not doing anything. I'm not going to talk to my neighbor at least just yet because I'm not charismatic enough and he will block me off.

>>2685799
Stop posting on 4chan from your grave, Chuck.

>>2685799
jam the 2.4ghz bands and watch him seethe

>>2685799
emf reader

>>2683331
Alright, stupid question: What would happen if I were to heat up a PCB-heater (Copper Trace Resistor) with a bench top PSU on the terminals and then apply a soldering iron (this one: https://www.conrad.de/de/p/toolcraft-jls-03-loetkolben-230-v-60-w-bleistiftform-200-450-c-588269.html)) to one of the terminals to melt the solder to suck it up with a pump (this one: https://www.conrad.de/de/p/toolcraft-lee-192-entloetsaugpumpe-antistatisch-2196503.html)?

The reason is that my 3d printer's heating bed shat the bed (pic rel) and the replacement will not be here for a while. I wanted to fix it for the time being. I tried heating the pads with the iron, but the solder became malleable and was pressed in slightly, it didn't melt because the pad literally connects to a heater with 220 Watts of thermal capacity while my iron can only supply 60 Watts ...

What PCB color do I get?

Green is slow
Purple is ????
Red is fast, but will catch on fire
Yellow is unreliable
Blue is good
White is right, white is good
Black is bad

>>2685871
>PCB color

/lgbt/ will be able to answer this best.

>>2685871
Slap a decal on for the silkscreen and clearcoat it.

>>2685881
That question is serious, since moment you use solder mask, you change destiny of the PCB. Making it pink, for example, will certainly make it suicide.

>>2685884
Pink PCBs have a 41% critical failure rate and scientists can't figure out why.

>>2685871
green because it tickles my nostalgia. as a child i loved to take apart old appliances to play with PCB's

I've an e-scooter.
It has 36V battery (10S) and it does 44 km/h (no load) and around 32-33 km/h with me going full throttle (maybe, idk, too scared to see how fast would it go kek).
And I've fucked up a battery (did a small lil hole in one of the cells trying to disassemble the thing).
Then I realized that I don't go any faster than 25 km/h and on 24V (7S) it would go 30-32 km/h no load, and maybe 25 km/h with load.

Question is, would it run more efficiently at 24V? After all, it has dumb square wave BLDC controller, and it is basically a glorified DC-DC converter, and I think that with lower difference between motor BEMF and battery voltage it would run much more efficient.
Not to mention that I'd have less losses in the battery as ESR would be lower (7S4P instead of 10S3P) which might give more/same mileage despite having less capacity.

>>2685831
>ecb BJTs
eh?

>>2685871
>Yellow is unreliable
please elaborate

>>2686012
Efficiency is usually somewhat higher at high voltages, because the ohmic losses (for given wiring and inverter) get lower for a given power output. But you're right that the ratio between BEMF and cell voltage makes a difference too. Ultimately these are just current spikes in the FETs, so you can probably calculate the losses at certain voltages if you have the Kv rating for the motor.

>>2686131
>Efficiency is usually somewhat higher at high voltages, because the ohmic losses (for given wiring and inverter) get lower for a given power output.
If motor is wound for that voltage. But I think it is not the case here.

There are two things in motor that are important. Torque and speed.
Torque is a function of current, which is limited by controller. If I keep 15A current limit, it would accelerate with exactly the same rate, until difference between BEMF and battery voltage drops to the point it can't push said current.
Speed is just a function of voltage.

When it comes to the current, losses in the motor are exactly the same (since both copper and iron losses are function of current iirc), but losses in the battery would be lower.
When it comes to the losses at 25 km/h... I dunno. I think that controller that works as a commutator (i.e. duty cycle is 100%) losses are smaller than when it works as synchronous buck converter (i.e. duty cycle <100%). And I think that buck converters (e.g. pic related) are more efficient when Vin is close to Vout. Which again, is better, since BEMF at 25 km/h is probably very close to supply voltage.
>Ultimately these are just current spikes in the FETs, so you can probably calculate the losses at certain voltages if you have the Kv rating for the motor.
KV of the motor is approx 1.0602 km/h per volt. A bit higher probably, because I've adjusted speedometer so it is a bit more pessimistic than reality.
But then idk the inductance of motor or frequency of the controller. I don't even know the resistance of the motor.
So its kinda hard to calculate absolute numbers, and relative numbers - idk either

>>2686131
>please elaborate
reminds me of shitty 00's AMD socket A boards.

>>2686156
Other thing, are FOC controllers more efficient? Because switching losses in them should be higher than in dumb square wave, but everyone tells they are more efficient, and all big industrial motors, no matter induction or perm. magnet, they use FOC inverters. Why is that?

>>2686159
>Why is that?
3-phase AC delta/wye

>>2686160
>>2686159
fuck, its really complicated, especially since there are different motors, some have sine bemf, some have trapezoidal... And idk wtf chink motor is since I've no scope, and i dont really want to blow up a laptop sound card.

>>2686156
>If motor is wound for that voltage
A motor isn't really wound just for a voltage, it's wound for a voltage and speed. A BLDC designed to run at 12S for drone use will want to run at a lower voltage if used as a direct drive hub motor, as I personally discovered recently.

>but losses in the battery would be lower
At a lower voltage they'll be sourcing more current for the same power output, battery losses will be the same.

Ultimately, as you increase the voltage, the ohmic losses in the wiring between the battery and driver get better but the switching losses in the transistors get worse.
When going for a lower voltage, either find yourself speed limited or torque limited. It's reasonably easy to measure the torque/current proportionality constant yourself, I strapped my motor to the top of my door, connected power resistors across its windings, and used it as a pulley for a weight to drag down. The motor got to a constant speed and I measured the voltage and frequency across the windings, which I could convert into speed and current values for the known torque.

>>2686159
They provide more torque for the same amount of current since there's less ripple torque. Team TMC4671 here.

>>2686162
Get an op-amp and a couple of optocouplers to make an analogue optocoupler for sound-card protection. Or get a USB sound card and USB data isolator cable. Or buy a cheap shitty handheld scope.

I just realised you could get good cheap soldering irons by making a box that measures the resistance of the heating element and TRIACs them for temp control. In order for the iron to heat up nice and quickly you'd get 110V irons and run them at 220V, because you're measuring their temperature via the element resistance there's no risk of the element burning out. It would mainly be useful in 220V countries, but I guess it also works where you've got 2x110V sockets like for a welder.

Bet you could make such a box for like $25.

minor soldering mishap

>>2686171
>At a lower voltage they'll be sourcing more current for the same power output, battery losses will be the same.
Yep. But overall power would be lower.
With 36V, its 540W, and with 24V its 360W, since can't really push much more current into the motor, because this happens even at stock motor currents.
Well, you can power in the controller, but it all options suck. Current limit will limit torque, and that sucks. Other option is to limit speed, which also sucks as it is quite abrupt and annoying.
>When going for a lower voltage, either find yourself speed limited or torque limited.
Given scooter has excessive speed, speed limitation isn't such big deal really.
So overall I suspect that efficiency improvements will mainly happen due to lower power (which can be achieved other ways), and slightly decreased switching losses (prob 5% improvement)
>Get an op-amp and a couple of optocouplers to make an analogue optocoupler for sound-card protection. Or get a USB sound card and USB data isolator cable. Or buy a cheap shitty handheld scope.
I've a better plan. How do I blow up an oscope in uni in such way they won't bother fixing it, yet I can fix it later on?

>>2686180
Unless it uses PTC heater, you won't be able to determine resistance precisely enough to have any meaningful control, furthermore, chinese 936 box is like 20 bucks or less, or some CXG iron is like 10 bucks. Why suffer?

>>2686195
>How do I blow up an oscope in uni in such way they won't bother fixing it, yet I can fix it later on?
I got myself a free scope from the uni through less duplicitous means (it's a hybrid CRT scope they didn't want to spend any more money on getting calibrated yearly), but you do you.

>Unless it uses PTC heater
Aren't all shitty open-loop irons PTC-based? Even if it needs calibration I think it should be doable.

>Why suffer
So I can turn this Yihua 929DV $15 desoldering sucker iron into one that doesn't melt my solder mask off and take 5 minutes to get hot.

What is this kind of part called? Is Tailpipe the only name for it?

Also if anon knows any similar clean options for a cord leading into a case

>>2686209
>Tailpipe

stupid, but funny, name.
normies would call it a cable strain relief.

>>2686209
Those screw-on cable glands are quite nice and really do provide good tugging relief, but they're not as good for angle relief as your pic. Personally for my last project I just tied the wire in a knot and fed it through a chamfered snug hole. 3D printed TPU can probably make for decent strain relief.

>>2686199
>Aren't all shitty open-loop irons PTC-based?
Nope.
Some heaters are thin film PTC (resistance increases, power drops, some irons do use this resistance to control temperature btw), some heaters are nichrome, and they barely change their resistance and thus power stays the same, and in case of 936 irons, if you don't control the temperature, heating element will heat up iron to cherry hot without any issues, and then die from overheating.
> Even if it needs calibration I think it should be doable.
Only with PTC. With nicrohome heaters you'd definitely need thermal sensor of some kind (usually thermal couple).
>So I can turn this Yihua 929DV $15 desoldering sucker iron into one that doesn't melt my solder mask off and take 5 minutes to get hot.
This one is nichrome heater and temperature is determined by how much does tip stick out and power of the heater.
Since you can't get temp feedback, your best option is to use a triac dimmer, and let iron sit for a while, and measure the temperature at the tip. If it is more than 350C - lower the power, if it is less than idk, 320, increase the power. Maybe you can make PID control of some sort, but response will be really slow, so idk.
>>2686209
Strain relief?

>>2686209
grommet with strain relief

>>2686234
Ah. Well even then I could still measure the resistance change of nichrome without too much difficulty, a shift of 0.5% would be measurable without too much difficulty.

>This one is nichrome heater
I figured they had some sort of PTC wire instead of nichrome.
>temperature is determined by how much does tip stick out
So the element itself gets up to temperature quickly and without risk of overheating, while they rely on the high thermal mass of the element or tip and the moderate thermal resistance from the element to the tip to "regulate" temperature? Like a thermal RC filter. Sounds awful, but I guess PTC films are expensive or difficult to work with. And because of that deliberately high thermal resistance from element to tip, it's impossible to make the tip heat up substantially quicker if I kept the element below ~500C anyhow.

Guess that idea is useless then, I'd be better off buying tips and handles for more expensive soldering irons and making custom stations for them. Like what the Aixun T3A does.

>>2686237
>>2686234
>>2686215
>>2686213
thank you anons

Im an idiot.. This USB cable has 5 wires. I want to wire it behind a usb-b male connector but theres only 4 points on it, so I assume the last one is ground. Where do I solder that one? Why do some cables have ground and some dont?

>>2686260
The fifth wire is the cable shield which in this case is the same as ground.

>>2686265
what do I do with it? Just ignore it or tape it away?

>>2686292
Tie it together with ground if it isn't already.

>>2686265
Why do they often completely separate ground and shielding? Why spend extra money for an extra wire? I've even seen a device which obviously used the ground of an USB cable for an extra signal, and used the shielding for ground.

>>2686260
>>2686265
>>2686314
could also be the ID pin which isnt commonly used

>got an idea for a project
>spend months researching every aspect and learning theory
>dig a few rabbit holes in between
>order parts
>sort parts in boxes, mark, pack, and store everything
>get into one of the previous rabbit holes
>got a new idea for a project
>spend months researching every aspect and learning theory
>dig a few rabbit holes in between
>order parts
>sort parts in boxes, mark, pack, and store everything
>get into one of the previous rabbit holes
etc
does anyone know the feel? how do i stay focused on one and just one thing?

>>2686387
OCD?

>>2686387
recognize bad habits and stop doing them
i.e. basic self-awareness

>>2686387
>how do i stay focused on one and just one thing?

your happiness comes from flitting from one project to the next.
why change that?
you'll just make yourself miserable.
like the rest of us.

>>2686195
>With 36V, its 540W, and with 24V its 360W, since can't really push much more current into the motor, because this happens even at stock motor currents.
Bullshit actually, I did some research, and apparently all motor controllers try to maintain phase current, not DC bus current, so on 24V it would consume a bit more current to get to the same phase current.
But duty cycle of the PWM would be higher thus more efficient.

https://www.youtube.com/watch?v=xBPwZzBhCvE

Sodium Ion batteries are real.

>>2683331
>Pride Month
kys

is there a way to make kicad DRC shut the fuck up about thermal vias?

>>2686584
oh wait nevermind im a dumb nigger, i had a pour going to a single layer rather than multiple layers.

>>2686569
based. energy density?

>>2686605
Shitty 18650. "9800 mah" tier.

>>2686574
It’s an IGBT/LGBT joke, pride should remain a sin.

>>2686622
Still worth doing for low-cost use where density doesn’t matter, like home storage. Hope they don’t stick to the tiny cylindrical cells though, they should be making larger prismatic cells like they do for LiFePO4.

Can’t watch the video at the moment, is it a nickel manganese cobalt design? If so that’s still a bottleneck.

>>2686637
>Still worth doing for low-cost use where density doesn’t matter, like home storage.
Yep.
If they would improve tech a bit, it would be viable for EVs and such.
> Hope they don’t stick to the tiny cylindrical cells though
Cells can be manufactured in any shape or form.
I think at the moment, some noname cell wrapping facilities are making these cells, and they might only have equipment for 18650s. (pic related, you can buy catode material)
>Can’t watch the video at the moment, is it a nickel manganese cobalt design? If so that’s still a bottleneck.
Unknown, but it very likely not lithium, and probably NMF... Dunno chemistry at all.
Discharge voltages don't fit any lithium battery and it doesn't have typical lithium battery "shelf" where voltage barely changes. It has somewhat linear discharge from 4V to like 2.4V and then it drops off to zero.

I'm kinda glad that this is no longer a technology from shitty eco-brainwash youtube video, but something you can buy and try out, albeit a bit expensive atm.

>>2686445
Nah I am still miserable. There are ways.

>>2683331
i'm trying to make a motor controller using the TI DRV8323. it states the input is 6-60V. how does it generate the gate driver voltage? i understand it uses a charge pump on the high side, but how is it dropping the low side voltage to the typical 12-20V absolute maximum for most NFETs when its input range is 6-60V?

>>2686569
https://www.youtube.com/watch?v=W1ya_ls1zkA
Hmmm... It's a bit more spicy pressure-wise, but less spicy fire-wise.
I wonder if these cells are defect with broken vent cap?

>>2686847
>DRV8323
Looks like the low-side gate driver's supply voltage VGLS comes directly from a linear regulator tied to the input voltage VM. I imagine VGLS is hence capped at no more than VM, as it often is with these monolithic gate drivers. If you do use at VM < 10V, I'd want to use logic level power MOSFETs. It also seems to use only a single charge pump for all three high-side drivers, and no bootstrap caps, which is unusual. VGLS also isn't being fed into this charge pump, so I guess it's somehow self-regulating even at high VM values. If you're lucky you'll get a higher high side drive voltage than VM, not that it helps much. Not too fond of the lack of a traditional bootstrap circuit, I hear it's more likely to give a spike of excessive gate voltage like that, though if there's an internal zener I guess it's fine.

The 1A gate drive is ok, but without the external bootstrap cap there's no external high-side power rail on which to slap a ZXGD300x. That's why I'll probably go for a DRV830x or equivalent Trinamic 3-phase gate driver IC, in conjunction with a TMC4671 FOC controller. Current sensing will be a pain.

>>2683331
why did you call this thread "Pride Month edition", what does September have to do with groomers? I thought they just "claimed" June?

Why is A. works just fine, but B. throws out 'convergence error'?

>>2687343
because simulations always need a well defined ground
put the ground node somewhere, anywhere

>>2687349

>>2687350
wtf are you even trying to simulate anyways, how is that feedback loop supposed to work?

>>2687371
Constant current LED driver.
The op-amp drives the MOS to achieve a currenty through the 500m resistor set by voltage divider on the non-inverting input.
If the input voltage increases, the op-amp throttles the MOS to maintain the same current, and vice-versa.
You can also do it with a BJT as pic related, but this uses the BJT's BE Vf as the control voltage. An op-amp offers more fine control.

>>2687383
when I tried simulating it (using magic ideal parts) i was getting 20v-kilovolts at the OpAmp's output. Try adding a feedback resistor of some sort from output to the base of the 1k resistor for stability.

>>2687383
>>2687350
>>2687343
I think that battery doesn't provide enough voltage and thus op-amp sends output of mosfet to stratosphere (since this is how ideal parts work, they just use an op-amp equation with no voltage limit) and it keeps on growing, which simulator doesn't like and gives you a convergence error.

Anyone have any recommendations on a hotplate for SMD soldering? I have no idea what to look for.

Also related question; Anyone here ever try making one of these DIY hot-plate PCBs? I find it kind of interesting.

>>2687570
Forgot pic

>>2687570
can't you just buy one for cooking? how hot do they even need to be

I asked this in a qtddtot but I think this may be the better thread
Can someone explain to me why devices on a L1 or L2 bus share wire numbers?

Shouldnt you be able to differentiate between lines? If you have multiple switches/buttons with power from the bus, how are you supposed to troubleshoot? Most drawings have the return wire labeled, why not the outgoing L1?

In pic related, shouldnt each button have a specific number on its left side?

>>2687311
Because I had a picture of an IGBT that I wanted to use for the op pic, literally no other reason.

>>2687570
I bought a cheap aliexpress mains hotplate and designed a PCB for TRIAC PID control. But I'm kinda retarded when it comes to design and it's sitting in development hell after somehow frying a MAX6675.

PCB-based designs are unsuited to handle soldering temperatures for minutes on end, as some on youtube have discovered. You're better off buying an off-the-shelf silicone or ceramic heater, sticking it to a flat plate, and embedding a thermocouple somewhere. I recommend just buying a mains temperature controller that's capable of changing the set-point via an internal custom program, or via a connection to a computer or MCU. Pretty sure PID controllers often have an ethernet or RS232 connection. Optotriac and zero-crossing circuits are a pain.

>>2687707
>shouldnt each button have a specific number on its left side?

if it did, it would mean the person who did the drawing is a maroon.
all the LHS wires are joined together, so they get all get the same number.
on a PCB or a schematic, the collection would be called a net, and all would be called NET 666, or whatever.
coz of logic and common sense.

>>2687820
I understand this in theory, but why does every single control panel I see have every wire on a bus labeled? And what's the method of this?

These labels arent on drawings, so how do people label these? Especially neutrals. Shit should just be all labeled N, but they always have specific labels

>>2687859
So you can check the neutral bar and find the one terminal for it or whatever. The neutrals are probably labeled by their position in the strip.

You have to read the age of labels and depth of the wire in the pile of shit too, it'll give you more clues on whats what.

>>2687862
So, you have a neutral "bus" and L1 "bus", each their own collection of let's say 10 terminals each. This doesn't need to show on the electrical schematic?

You can just label them TB-1, TB-2, etc? So for a button, you'd have one side with "TB-1", and the other side with the wire number as seen on the electrical schematic. How does one know then if all those items are on a bus or simply jumped in field?

>>2683331

>>2687883
are there really bots on /diy/? i can see that being a good idea for /g/ and the red boards, but this board is slow even if it has bots

>>2687883
>>2687886
>i can see that being a good idea

Stupidest idea that ever got spammed here. On that day, in addition to all the normal shit that normal idiots will post, we'll have a million idiots calling everyone else a bot.

In other words, 4chan at its best; idiots competing for the idiot of the day award. so keep spamming your pathetic idea.

is there a way to force an ideal choice for conflict net classes in kicad? im doing low side current sensing. i have a net labeled "SNA" but it bitches at me about a name conflict and forces it to "GND". i want to manually assign it to "SNA" to make pcb layout easier.

>>2687707
>>2687865
When schematic is drawn as shown - it's all logically and electrically same net. So it does not make sense to label each wire separately.
If shit goes somewhere off or there is some terminal block on bus as splitter - it should be shown somehow in schematic and potentially each segment getting it's own net.

There are standards that would enforce labelling each wire segment but it's generally not enforced for industrial applications.

>>2687993
use net tie. I think kicad allows creating net tie components - custom footprint, two pads and join them together.
Alternatively - either some jumper resistors or rename GND to GND_SNA or something similarly retarded

i have this t212 hammond organ, works fine but its not valuable or anything. i was planning to take the leslie unit out and make it a standalone speaker cabinet, but now im wondering if i can just pull all the amplifier guts and make it powered. i know theres tons of stuff online about modifying organ amps, but i cant find an answer as to simply deleting all the keyboard stuff and hacking in a line input...any one know about this?

>>>/vg/447875110
Artificial Academy 2 General /aa2g/ #1293
Ready to Serve Edition

Welcome, this general is for the discussion of ILLUSION's Artificial Academy 2.

COPY ERROR MESSAGES WITH CTRL+C, PASTE THEM WITH CTRL+V INTO GOOGLE TRANSLATE. JUST CLICK THE WINDOW AND PRESS CTRL + C, IT WORKS.

>Downloads:
/aa2g/ Pre-Installed Game, AA2Mini: https://tsukiyo.me/AAA/AA2MiniPPX.xml
AAUnlimited updates: https://github.com/aa2g/AA2Unlimited/releases

>Information:
AA2Mini Install Guide:
https://docs.google.com/document/d/e/2PACX-1vS8Ap6CrmSNXRsKG9jsIMqHYuHM3Cfs5qE5nX6iIgfzLlcWnmiwzmOrp27ytEMX03lFNRR7U5UXJalA/pub
General FAQ:
https://web.archive.org/web/20200216045726/https://pastebin.com/bhrA6iGx
AAU Guide and Resources (Modules, Tans, Props, Poses, and More):
https://docs.google.com/spreadsheets/d/17qb1X0oOdMKU4OIDp8AfFdLtl5y_4jeOOQfPQ2F-PKQ/edit#gid=0

>Character Cards [Database], now with a list of every NonOC in the megas:
https://docs.google.com/spreadsheets/d/1niC6g-Xd2a2yaY98NBFdAXnURi4ly2-lKty69rkQbJ0/edit#gid=2085826690
https://db.bepis.moe/aa2/

>Mods & More:
Mods for AAU/AA2Mini (ppx format, the mediafire has everything):
https://www.mediafire.com/folder/vwrmdohus4vhh/Mods
/aa2g/ Modding Reference Guide (Slot lists for Hair/Clothes/Faces, List Guides, and More):
https://docs.google.com/spreadsheets/d/1gwmoVpKuSuF0PtEPLEB17eK_dexPaKU106ShZEpBLhg/edit#gid=1751233129
Booru: https://aau.booru.org

>HELP! I have a Nvidia card and my game crashes on startup!
Try the dgVoodoo option in the new win10fix settings.
Alternative: Update your AAU and see if it happens again. If so, disable win10fix, enable wined3d and software vertex processing.
>HELP! Required Windows 11 update broke things!
winkey+R -> ms-settings:developers -> Terminal=Windows Console Host

Previous Thread:
>>>/vg/445943839

>>2688077
>can just pull all the amplifier guts and make it powered

you have the opportunity to replace that ancient monstrosity by a super kawaii Lepai LP-2020A, and you are hesitating.
something wrong with you, boy.

>>2688109
do ohmfags really?

>>2688111
interdasting, so with that thingy i can feed in a guitar signal and send it to the leslie, you reckon it will sound well enough huh?

>>2688117
>guitar signal

i dont know much about guitars.
seems they can put out as much as 1V but need a high impedance amp, like 1meg.
so, likely you'd need a pre-amp, maybe just a pedal preamp.
the Lepai, like just about every amp, has an AUX input, which means a signal about 0.1Vac

>>2688117
You might need a DI box.

>>2688125
>>2688124
ok ty sirs

>>2688124
guitar has a Vppk of 50-400mV and output impedence of 100k or so (might actually be 10k, they define "impedance" as what load they can drive so probably closer to 10k)

>>2688180
So let’s say the output impedance is 10k ohm.
Is there any harm or negative effect of driving a 10 M ohm FET op-amp preamp??
Perhaps an impedance matching transformer. I think that might be too many turns though and have other negative effects.

>>2688210
>Is there any harm or negative effect of driving a 10 M ohm FET op-amp

shouldnt be.
in fact, it should sound better as 10K/100K input impedances tend to attenuate the high frequencies.
the one advantage of lower input impedances is you'll get less hum if the cable is inadequately shielded.

>want to rewind mot for 24vac
>need 18 turns for the right voltage, seems easy enough
>normal dc power cable has insulation that's too thick
>consider multiple parallel windings of enamel wire
>the thickest stuff i can easily get is 1.25mm diameter
>do the math
>would require 20 windings in parallel
i really don't want to spend a dozen + hours of my life making 360 turns through a closed core

>>2688303
It would take less time than knitting a a scarf for your mom.
You can divide down the time by computing the length and twisting, say, 4 pairs at a time with your drill. Also, you have litz wire! You can use higher frequencies than 60Hz with fewer losses.

>>2688326
ligma nitz, litz

>>2683331
I'm thinking of doing some Welding at home. How should I go about modding my home's power to mainly account for a Vulcan ProTIG 165? Curious anon.

>>2683331
I also have a 110v S7 Stick Welder at home - but sadly it's maximum amperage is only 113 amps (actual - because it's one of those "muh heckin' 200 amperinos!" but in reality it only displays double the actual number - which is retarded).

>>2688326
>You can use higher frequencies than 60Hz with fewer losses
I'm modifying a MOT because I want to see how cheap I can get an EDM PSU, and because I want a low-effort power supply as a test rig for my kW BLDCs. If I wanted to bother designing a 2kW off-line AC-to-DC converter I'd just buy a nice toroid.

That said, 24V (48V with split rectifier) is kinda low for an EDM PSU, so maybe trying to get a supply to do both the motors and the EDM is silly. For the EDM PSU I could go for whatever is most convenient, in this case it would be using the entirety of a 9m roll of 1.25mm cable for each parallel winding.

>>2688339
Ask the sqt thread, metallurgy/machining thread, or welding thread if there is one. My guess is you want to plug it into a conventional 240V outlet (electric oven outlet for americans), if not a specifically high-current outlet variant (15A, 20A, etc.).
Read the welder's spec sheet too.

>>2688342
Will do anon.

>>2688340
>110v S7 Stick Welder

i have something similar. it has a 120V/240V switch, but it's useless at 120V.
since i dont wanna unplug my stove to get 240V, i made something similar to this.
except the female is just a normal 120V-looking female from an extension cord.
you need to connect to 2 diff power sockets, each on a diff phase.
you'll prob find some like that in the kitchen.

>found dead laptop battery in the trash at home that I stole from e-waste trashcan 5 years ago
>3/4 cells had 3-3.6V
>1 cell had 1.17V
Made me think, is it worth making an automated recycled (or maybe chink) battery tester and matcher?
A device that can charge cells, discharge cell (and instead of heating the air, charge other cells under test), measure temperature and all this while logging voltage, current, time and temperature?
You put in cells, on the end it tells you the capacity, ESR, temperature, or if cell is junk. And with some software magic it can build a battery pack where all parallels are matched as close as possible.
All commercially available solutions suck as they dissipate energy as heat (imagine wasting free energy) or don't log as much stuff, and don't talk to computer.
In general, a device with DC-DC converter per cell, in order to either provide energy to DC bus, or take energy from it, kinda similar to what active battery balancers do. And bunch of op-amps with micros to talk via I2C or UART or idk, whatever bus, waiting for commands.

Basically, an industrial grade equipment that is probably used at battery factory, but modular, programmable extensible and

>>2688339
Just add whatever circuit a welder might need.
>>2688340
I've bought similar chinese box too. I did pop IGBTs in it, and stopped trying to turn in into a lab bench welder.

>>2688403
I think it's worth doing if you get a lot of those cells. Make it take like 8 cells at once, perform charge-discharge analysis on the lot. Then you could use that data to properly match them in new packs.
>a device with DC-DC converter per cell
It's a lot more complex to have a DC-DC converter for every single cell, as opposed to just using BJT+opamp current sources and sinks. I'd just bond the heat-sink to something that could benefit from heat, like my hot water cylinder, some desiccant that needs drying, or maybe a biltong box.

>programmable extensible and
and what?

>>2688412
>I think it's worth doing if you get a lot of those cells.
Pretty much yes. If you have three cells, that's three cells, you can't even optimize a 2S pack that much lol.
> Make it take like 8 cells at once, perform charge-discharge analysis on the lot
I was thinking of a device that can do it just to one cell, but it has the DC bus connector, and data lines, where it can dump/take energy and well, receive commands. And a master device, that has a big ass power resistor (in case if all cells are charged), power supply (in case if all cells are dead), and whatever interface to usb converter.
>It's a lot more complex to have a DC-DC converter for every single cell,
Yes, but for example, that's what Lii-500 does, at least for charging. And it is possible to use bidirectional DC-DC converters. Or it might be cheaper to use step-up for discharge and step-down for charging, idk. That's a bit unclear what to do, but it has to be DC-DC, otherwise its kinda lame... Unless its winter lol.
>programmable extensible and
>and what?
Lol. I probably means programmable and expansible/scalable or whatever.

>>2688422
>means
meant
ffs

>>2688422
If you have like 50 cells then it's going to take ages to get through them by swapping them out every 4 hours or whatever one by one.
>dc bus
do you mean to have a storage battery?

>>2688432
>do you mean to have a storage battery?
Either a chopper circuit (like in trains, where energy is dissipated in resistor when there is no consumer), or yeah, a battery.
After all, if you're dicking around with e-waste cells, you probably have a battery of sort. Doesn't matter, e-bike, powerwall, whatever.
>If you have like 50 cells then it's going to take ages to get through them by swapping them out every 4 hours or whatever one by one.
Idea is to have multiple testers working in conjunction.
Master device has said chopper circuit, PSU or battery, and whatever interface converter.
Slave device has bidirectional DC-DC to charge/discharge cell into/from common DC bus, and measuring stuff.
Or idk, make master device ADC switch between various slaves to measure voltage/current at a certain timestamp.
More slaves you have, more cells you can test at any given time, more energy you save by moving charge instead of just converting it into the heat.

>>2688439
Something like this.
Well. Reality is that it probably would never pay for itself, not even in Europe. Unless you're processing 20+ kWh worth of e-waste cells.... But then, it is possible to make a simplified version with just one DC-DC for charging and BJT+resistor for discharge.

>>2688444
If you can get a cheap off-the-shelf bidirectional buck-booster module to just slap together with an MCU and current sense amp then I can see it being economical. Otherwise maybe you can make a cheap H-bridge converter with a master-slave pair of cheap switching controllers plus cheap gate drivers like the EG2131. I think TL494s might work for this, idk.

Personally I think it's more economical to have one MCU controlling several cells. Maybe you have a self-discharge test where you idle one cell, in which case it would be possible to just have a single DC-DC converter being used for two different cells.

hey, sorry if this is a stupid question but i need help with finding a specific kind of IC
im trying to design something that can sense the continuity of a jumper wire by letting a very small current through it, and then turn that into a logic value. ideally id do this through some sort of small ic chip and not a voltage divider, since i dont want to waste analog i/o pins on my rp2040 for voltage sensing.
is there any chip that can do this?
pic related is sort of what im trying to accomplish

>>2688461
comparator?

>>2688462
yeah that'd probably work, thanks
sorry if that was obvious, im still pretty new to this sort of stuff

>>2688463
A schmitt inverter/buffer gate (maybe a 74lvc1g14 if you want something really small) would be even easier, if you're fine with a middle-of-the-road voltage threshold and a large hysteresis. You probably do want hysteresis anyhow.

Herro Anon.
So I found this joystick 4 position controller in the dumpster
>want to convert to usb
>only have arduino nanos lying around which apparently don't have built in HID support
>wat do?
Found this on the internets:
https://github.com/obdev/v-usb
Is this a realistic project for an MCU n00b?
Is it even possible with an ATmega328P ?
I thought I'd start with this example project. https://www.obdev.at/products/vusb/hidkeys.html
Looking at the makefile would it sufficce to just change the appropriate lines for the compiler and programmer?

I figured I'd ask here since MCG is pretty much dead.

>>2688553
dude just buy a mcu with native usb. thousand times easier and cheaper in terms of sunk time cost

>>2688553
>have junk, wat do?
Shitcan it

>>2688553
>ATmega328P
The P stands for poop.

>>2688553
Get a Raspberry Pi pico you dumb fuck. It's about the same price.
>>2688650
Kek, can confirm.

TL;DR: I can't figure out why my motor stops spinning.

I'm trying to drive a single stepper motor with an a4988, an Arduino knockoff, and a PC PSU. Although jerky, the motor spins at first but becomes weaker until it stops moving after 10 seconds. Voltage reads ~1.7V in the beginning and trails off from there. The 12V volt line, however, stays pretty consistent.

Motors are salvaged 17PM-K402-P4V. Bipolar windings read 12ohms. Even if I am under-volting it, as I suspect I am, that doesn't explain this behavior. Any PSU wizards want to enlighten me?

How easy/expensive would it be to take grampa's old broken radio, take out the insides and put some bluetooth-enabled, good sounding speakers? Assuming I'd like the buttons on the front panel to still do something (on/off, next song, volume, ...)

>>2688696
>good sounding speakers?
What do you mean by good sounding speakers?

>>2688698
lmao forgot about the audiophile menace. Literally anything that doesn't sound like it's coming from a tin can. Normal JBL bluetooth speaker quality. Which I happen to have actually. So I wonder if I can just break the JBL's case, pull out the insides and rewire it to gramp's old radio's buttons?

>>2688699
>Literally anything that doesn't sound like it's coming from a tin can.
If you want to have at least some bass and reasonably full-range response you will have to build some sort of enclosure that is matched to a driver. There are plenty of enclosure calculators on the internet, you just need to put in speaker parameters. It's probably not worth breaking your JBL speakers, because engineers already did their homework and built a proper enclosure.

>>2688699
I wouldn't even change the drivers. Literally just put a bluetooth amp from ebay inside and connect it. I've done this to quite a few old radios and they sound way better than you'd expect.
Of course you're not going to get home theater bass but try and you might be surprised.

Search 2*15w bluetooth amplifier on aliexpress/ebay - they're like 4 bucks.
There's no need to get a 4 channel one if the radio has two tweeters, those are just generally filtered with a single capacitor.
The other anon is right about the jbl speakers. They'll have a bunch of dsp correction already applied which is going to be less ideal.

>>2688553
Yeah it's possible with V-USB, it's a hacky method though. Also you'll need to either use zener diodes and resistors to your data lines, or to run the thing off a 3.3V rail (resistors are still a good idea). Either way you need a seperate USB port because the port on the Arduino is directly connected to a CH340 USB-to-serial adapter, I recommend an old full-size USB B socket, since their pins will fit easily into perfboard. Alternatively, if you have an Arduino Uno with the dedicated ATmega16U2 as a programmer instead of a CH340, you could program that via a seperate Arduino-as-ISP or USBasp. You will need to write code to transfer data between the two ATmega chips (the UART pins are connected already) because the 16U2 (or 8U2 or whatever) doesn't have any GPIOs.

>>2688684
My guess is the driver is overheating and thermally throttling.

>>2688684
Shitty breadboard connection.

>>2688763
What the heck is V-USB?

any books for learning the basics of how to use BJTs to make analog designs? like straight up walking me through things like a retarded person. i know the basics of how a BJT works but i'm too dumb to intuitively grasp how to actually do anything with them.

>>2688780
Bit-banged USB, from what I understand.

>>2688782
That's exactly what it is, and it's very useful for shitty AVRs. USB 1.1 is fine for a lot of stuff.

>>2688781
The books in the OP should describe transistor topologies.

Generally 99% of BJT uses will be:
>common-emitter - high voltage gain, low current gain, inverting
>common-collector - low voltage gain, high current gain, non-inverting
>common-base - high voltage gain, low current gain, non-inverting
If the transistor is being used in saturation (e.g. as a switch), chances are it will be common-emitter, while if it's being used linearly (e.g. to pass an analogue signal) it could be any of the three.

The common BJT amplifier topologies are:
>class-A - simple and inefficient, produces distortion with even harmonics
>class-B - less simple, produces distortion with odd-harmonics
>class-AB - somewhat complex, produces little distortion when tuned properly
These are the main uses for BJTs in low-frequency (e.g. audio) uses, but for RF uses you may see class-C amps, or less trivial constructions of multiple common-x topologies like the cascode.
There's also differential topologies like the long-tailed pair, which aren't used discretely very often but are the backbone of operational amplifiers. Same for current mirrors.

I recommend researching both the topologies themselves (I think W2AEW has some good videos on these) and looking at the circuits people design with them (sound-au.com should have most of them).

>>2688765
>>2688763
Turns out I overlooked the importance of connecting the sleep and reset pins on the driver. Thanks for the help though lads.

>>2685853
crack out the heat gun and preheat the board, so it can compensate to your gayass soldering iron

>>2688582
I wanna learn though. I just don't know where to start cause I'm overwhelmed by the amount of ressources available.
But luckily I found someone has already done pretty much what I had in mind.
https://raffsalvetti.dev/2023/07/attiny85-gamepad/
>>2688763

>>2688940
or he could just connect it to 24VDC for 10 minutes using alligator clips, self-heating board
pretty sure my 70W station would get through that board without pre-heating if set to 400C (maybe 450), while an Aixun T3A or other 200W T245 station would do it effortlessly.

>>2688964
Also see Mitxela's projects, he's done a lot with V-USB.

>>2688782
V-USB is great.
I’m using an nvidia 4090 and a years worth of cuda core programming to get USB 2.0 speeds through the dvi port.

>>2689196
Lmfao. Is there a practical purpose or is it just for the lulz?

>>2689200
I’m just trying to say it’s a nearly worthless endeavour. USB is something that shouldn’t be bothered with unless there is backing hardware support. Even a shift register would help.

how do guys cope with software chads making 3x more money than you and there being zero jobs in hardware

>>2689287
> software chads
It has always been thus.
In my city the bus drivers went on strike, yet it became known that they made more than university professors.
In my company, the high-school dropouts in the support and customer service department make more than the C/C++ developers.
Take a look at the state of software… it’s now become a huge self-propagating scam. “Frameworks” like angular are more complicated than operating systems just to throw up a hello world page.
Most of the younger crowd (last 20 years or so) in software are completely ignorant about electronics or how processors actually work.
The enlightened will eventually turn back to the origins of everything and embrace hardware again when they realize they can wire an inductor and capacitor to make a filter instead of using a 3GHz 64-bit processor with DSP extensions to extract the power/frequency spectrum from a FFT at a thousandth the cost and a billionth of the efficiency.

t. software chad.

>>2689287
software dev is suicide inducing and money isn't a problem

>>2689287
Have you seen how saturated the CS market is right now? Go on cscareerquestions sometime. Every person on there is about to commit suicide

>>2689361
everyone there is probably a ngmi sperg who fills junk apps and can't even make eye contact with their interviewer

Lemme see if I've got this right:
>Inverting amplifiers are fairly stable, but prone to miller capactitance
>Non-inverting amplifiers are high bandwidth, but prone to oscillation
Is that an accurate generalization?

I've seen so many amateur designers slap together these weird hodge-podges of inverting/noninverting amplifiers without any rhyme or reason, was wondering if this could clear things up

>>2689806
Sounds about right. Though in the domain of transistor amps there’s the case of the common-base/gate amp, which is pretty stable as far as I know.

>>2689828
>common-base/gate amp
those are just unity gain current-to-voltage converters from what I can tell

>>2683331
Can someone find me a servo that is at least as fast, has as much or more torque, but is able to go 360 in either direction?

Come on /ohm/ let's build a device and sell to hipsters. Some kind of a flashy button with multiple colors. How hard is it to make $$$ selling custom thingies? Ordering parts on LCSC and boards on JLCPCB is cheap. The markup could be 70% according to my calculations. I need some pocket money.

>>2689918
MOS-tube amplifier.

>>2689840
>unity gain
The current gain is 1, the voltage gain is larger than 1. But they have a very low input impedance, so it's kinda hard to use them as a voltage amplifier without using them in conjunction with a voltage buffer. They make a neat combo with an emitter follower. Though I've never seen such an arrangement, I just see cascodes instead. I don't understand.

>>2689905
Look for a brushless servo instead. If you want actual advice, ask /rcg/.

>>2689918
PCB stylophone, but it's a meme soundboard using capacitive touch aimed at streamers and insta-thots. If it detects excessive capacitance indicative of having had a drink spilled on it, it plays the wet fart sound effect. Make it with a leaded tin finish, to play our part in darwinism.

Though I'd rather crowdsource a TS100-style iron that uses an EC3/XT30/XT60 connector to get the full 200+W to a T245 tip. Sell it to RC hobbyists.

>>2689927
>200+W

would a tea light and half a coke can be enough to make a solder pot? I just wanna strip and tin some fine enameled copper wire i stole from my last job

>>2689931
Finally, I can desolder consumer electronics.

>>2689931
>>2689938
i dont understand how desoldering consumer stuff works. it's literally impossible without all kinds of weird tricks. I once hit a board with a butane torch and the board itself (to say nothing of the components on it) melted before the solder did.

>>2689941
You did it wrong.

Im reading from a linear hall effect sensor and want to smooth the signal a bit on the hardware side before I do averaging stuff in code. Would this be as simple as adding a cap to the input.

>>2689931
you have yet to see the light of high-power closed-loop temperature control, where you can power through ground planes and fully heat up in 10 seconds, without deviating into sketchy temperatures

i just want picrel but not chinkshit

>>2689977
You want a low-pass RC filter. The corner frequency f is defined by f = 1/(2π*R*C). Pick your corner frequency to be roughly the maximum frequency you care about measuring. A simple passive RC filter will fall off at -20dB/decade.

>>2689989
>i just want picrel but not chinkshit

if you've got the dough, you can get the best of the best.
made in ameryka.
metcal.

Ok turns out 8 turns of 8awg is not enough for an appreciable voltage. I'm getting about 8V, with rectification I could turn that into 10VDC, 20VDC if I use a

>>2689997
>120W
>$550
I'd be better off just buying a 200W Mean Well PSU, a JBC branded T245 pencil and tips, finding the DIN socket it uses, and throwing together a controller with TS100/pinecil firmware on it or whatever. Might even be able to get JBC firmware on it if I pick the right chip (or use an FPGA emulator lmao). Would cost like $150 and would perform better.

That said, Metcal's inductive soldering setup does look pretty neat. Looks like instead of a conventional cartridge tip, the inductive coil unit is seperate from the tip itself, and it heats up the tip directly via induction. Opens up some interesting avenues for high-performing custom tip geometries, if I could figure out the temperature sensing method. Might buy a DIN-8 connector and mess about with a Metcal pencil if I find the time.

>>2690002
... 20VDC if I use a twin rectifier. That's enough for some stuff, but not for the kind of motor driving I'm after. I'll try winding this 8awg on a larger MOT I have.

>>2689938
>Finally, I can desolder consumer electronics.
You should try your hand at stained glass windows.
>>2689941
>i dont understand how desoldering consumer stuff works.
Study moar. It's easy when you know the secrets.

Can you buy this fire sword without a loicense in the UK?

anyone aware of any scripts or templates for kicad 7.0 that have jlcpcb's multi-layer capabilities preloaded?

>>2683331
Will this work as a 5v charger?

why it's 6v here not 12v? :)

>>2690071
The filament in the bulbs are resistive and they create a voltage divider/resistor divider.

>>2690069
No. What are you trying to charge anyway?

>>2690072
but why it becomes 12v again after second bulb?

>>2690076
It depends on where you place the probes.

>>2690076
In your pic >>2690071 if you move the red probe to the other side of the bulb on the right, you'd be measuring the potential of the battery (12V).

>>2690076
>but why it becomes 12v again after second bulb?
https://en.wikipedia.org/wiki/Kirchhoff%27s_circuit_laws

>>2683331
So get this guys. I'm doing a simple contact switch for an ancient forklift who needs a push button for the starter motor and one for lights. It also needs charging from the alternator to where I put 12v from the switch to the exciter pin on the internal regulator from the alternator. All works great till you flick the switch a few times and the exciter wire corrodes the internal contacts of the switch because it's making spark. So my question is how do I stop a connection from making spark anytime it's being switched? I tried putting a diode in line but didn't help. I was looking up now how to make a voltage regulator from a MOSFET and potentiometer to make it a proper alternator but that thing takes up 3.4 A on the excitation.

>>2690174
Use a fuggin starter relay.

>>2690069
your zener is backwards and upside down
also a linear regulator is going to be much more stable and efficient than a zener regulator
also you want more than just a constant voltage for charging a battery, some form of current limiting is a requirement

>>2690174
freewheel diode (it goes in anti-parallel with the coil, not in series) or snubber network if you're too autistic to use the dedicated hardware

>>2690181
Oh shidd

>>2690252
get outta my friggin thread, fryman

I took apart an old electric toothbrush, and I was looking at the circuit, and I saw this 6 pin chip? labeled
>KLB

apparently googling that just talks about LED, anyone know what this is and where I can read more about it?

>>2690297
According to
>https://smd.yooneed.one/code4b4c.html
it's a BAT54BRW diode array.

>>2690307
>BAT54BRW

Sorry anon! When I was googling it I just used an already existing image online. I will upload a pic of mine to get a more accurate answer.

>>2683331
i want to make a 0-1 mhz, 0-100% duty cycle pwm signal. i know this is theoretically doable with some op amps or comparators, but how hard is this to get working in real life with real parts over such a large dynamic range of frequency and duty cycle? should i just say fuck it and do it digitally with an ad9833 IC?

>>2690343
should be trivial if you can find a 555 that can go that fast, or learn to program an arduino (in C, not the stock libraries)

I wonder, why don't chinese controller manufacturers make something neater than just rat nest of wires?
There is plenty space to put on wago knock offs (lol, we will see if it is a fire hazard or no, and in case it is, I will replace it with original ones)... Pretty sure instead of silicone condom with wires poking through they could have put a small PCB with, idk XT60 for power, MT30 for motor and whatever connectors they use (SM with 2.54 mm pitch?)

>>2690220
I want to develop a wireless charger, but this is to show I can charge lithium batt with a 12v car batt. my retail charger is blown, uses regulator so it's crap

>>2690379
For lithium ion, you want a CC/CV charge circuit, with the voltage set to ≤4.2V per series cell, and the current set to something sensible for the size of cell you have (≤1A for a single parallel 18650). Those values will be different for a lithium ferrous phosphate cell. Some smart additions would be a recovery mode that uses much less current when the cell voltage is really low, and a current cutoff latch that turns off the charger once it's finished to protect the cell (they don't like having 4.2V put across them for hours on end).

You can make such a circuit with two LM317s, but it won't be that efficient. If you plan on making a wireless charger, you'll almost certainly want to use a switching converter since you'll have a power bottleneck in the wireless stage and will want to make the most of what you can get. You'd do well to read some appnotes on the topic of wireless charging, chances are there are dedicated wireless charging PMICs that will receive the wireless power transfer and give a proper CC/CV charge curve to a lithium ion cell. Though there's nothing stopping you from making a more diy circuit using a switching controller IC like the TL494, which has two exposed feedback loops that you could relatively easily use for CC and CV.

Can you get these things but the batteries are wired up in parallel? Or should I just get two individual boxes and wire them up myself?

>>2690421
>Can you get these things but the batteries are wired up in parallel?

not in this universe.
maybe in a parallel universe.

>>2690399
Thx, I will follow you advice. Here is Wireless receiver in pic, will build a transmitter.

>>2690421
you shouldn't put battery's in parallel, they might damage eachother with high currents coming about when the low internal resistance meets even a small imbalance in charge before getting connected in parallel.
a (pair of) resistor(s) might solve this, depending on your application

Can i measure the wattage going through a speaker by placing my multimeter in series with it while playing music?

>>2690667
The diaphragm has a positive and a negative in the back you can measure those?

>>2690667
https://rftech.custhelp.com/app/answers/detail/a_id/468/~/measuring-amplifier-output-power

>>2690672
Just the normal + and - leads for audio.

>>2690675
That's dead simple. Should i use this as the test audio?
https://www.youtube.com/watch?v=Jj017EPJBa0

>>2690681
You should use 1kHz @ 0dB for the mid/high test and 50Hz @ 0dB for the sub test. Whether you generate it locally or stream from jewtube doesn't matter.

I'm trying to use a relay to shut off power to one plug when a different device is running (not enough power for both to run at the same time). I have a relay that should work, but the signal to flip the relay is only about 5v and needs to be 9-12v. Is there an easy way to boost voltage or am I going about this the wrong way?

>>2690726
Is it a latching relay or one that needs constant power? If it's latching you can just send it a short pulse of the needed polarity, which could be done by an inverting-boost-style circuit (without the filter cap) or use a charge pump to fill up a capacitor with a doubled voltage. If it's not latching then you'll probably need a boost converter since charge pumps can't output that high of a continuous power.

Latching relays are the optimal method for avoiding a high quiescent current.

>>2690741
I have 2 tankless water heaters, one for in floor heating and one for domestic hot water. I need the in floor heater to shut off when the domestic runs. There is a flow sensor built into it and would like to use that signal to trigger the relay to cut the pump for in floor. Relay is pic rel, plug is wired and relay works but not enough voltage to trigger it.
Would something like this work?
https://www.amazon.ca/Converter-Voltage-Adjustable-Step-up-Circuit/dp/B07L3F9PV3/ref=asc_df_B07L3F9PV3/?tag=googlemobshop-20&linkCode=df0&hvadid=341851109660&hvpos=&hvnetw=g&hvrand=13528092037682298568&hvpone=&hvptwo=&hvqmt=&hvdev=m&hvdvcmdl=&hvlocint=&hvlocphy=9001291&hvtargid=pla-722994525988&psc=1
I'll send you some internet money if you help me figure this out. Thanks

>>2690769
Use a 12V wall wart to power the relay (don't forget the flyback diode), and isolate it with an optoisolator or transistor + passives.

>>2690769
Yeah as the other guy says it's probably easier to run a 12V power supply. Why do you have 5V in the first place? A low-power microcontroller + sensor? Generally you pick the primary power supply to be at the right voltage for whatever consumes the most power, which in this case could well be the relay. Then you could just have a 7805 or whatever powering your 5V circuitry from the 12V rail.

Though if you already have a 5V rail that's not going away, yeah an adjustable boost converter should do the trick. Switch the relay using a transistor of some sort, and don't forget the diode across the relay coil.

My steppers are running hot. Like 80C+ plus. Im running stepper motors in stealth mode
>tmc 2209
I need for recording data. Trying to focus while theres a high pitch siren in my ear was driving me crazy. But the motors are getting incredibly hot. Like I cant touch them hot. Is there a way to prevent this behavior of stealth mode other than to turn down the current until theres barely any holding torque. I would ignore it but its definitely hotter to the touch than the heated bed I used to 3d print the mounts out of petg. So its hotter than 80C and its also probably gonna melt the petg mounts away. Im so far in the design that I incorporated the elasticity of petg into my design so I have to keep the motors below at least 70.

>>2690820
I think this is the wrong general. But it sounds like your current control is either turned up too high or isn't working at all. Stealth mode might result in your driver getting hotter due to the higher switching losses, but the motor itself shouldn't be getting any hotter than normal. Check the stall current and the trimpot voltage, see if they align with one another and if they're set to a sensible value.

Don't suppose your mainboard has more than just the step/dir lines going to the driver, does it? If it has UART lines too you'd be able to tell the driver to change its current dynamically. Same applies to having an analogue line connecting your current reference pots to a digipot or whatever.

>>2690826
This is for a parallel robot but I probably should have asked in 3dpg anyways just in case. The drivers are just plugged into a breadboard and driven by a teensy. I didnt want to deal with uart yet. I was originally using a4988s but I couldnt stand the sound so I didnt change the code for uart mode.
I found the issue though. Since you said they shouldnt be getting hotter than normal I checked the vrefs again and they were cranked up to 1.8v. I gave them a small twist to lower the voltage after my initial check but its like the pots on the drivers needed to be broken in because I was getting crazy values from each turn.

>>2690830
Get rid of the breadboard.

>>2690833
Ideally, but I need to use the teensy for multiple reasons and I had a few laying a round.

>>2688817
Totem pole is most common

>>2690859
how tf do those even work

Here's the motor driver sub-board, test fitting against the power half-bridge board itself. The idea is to order a selection of highly versatile boards from overseas boardhouses for cheap, and adapt them for specific projects using home-etched single-sided boards for faster turnaround and prototyping.

In this case I'll just be controlling a single half-bridge using an ATtiny13, but in the near future I'll make a board that has three of them acting as a BLDC driver.

>>2690884
Ok black solder mask was a mistake. Hope I don't have to bodge it.

>>2690899
Why would you put on soldermask anyway?
Soldermask didnt exist for years and shit worked fine

>>2690916
> fuck solder mask
Anon is correct. Solder mask is for the wave soldering process.
Since then, it’s become a cargo cult ritual with no understanding or perspective from whence it came.

>>2691013
I think best examples of this are 1980s computers.
Top has no solder mask, bottom has soldermask, because wave soldering.
So yeah, there is no reason to put on soldermask on home made PCBs. But if you're ordering PCB, might as well just put on the soldermask lol, comes free of charge anyway

>>2690916
>>2691013
>>2691025
Yeah if you're just talking about coarse pitch THT boards then I'd agree there's no point in solder mask. But I'm running traces underneath SMD parts here, I don't want invisible bridges forming. Same for if you're running THT parts with traces between their pads. High density PCBs necessitate a solder mask to prevent bridging.

Also it stops the copper oxidising without having to tin-plate it. More importantly, it holds the traces to the board in the event they start to delaminate, which is quite relevant considering I made this board on FR2.

>>2691082
Idk you could have applied it just in suspect places.
>Holds traces
Not really, fr2 is just shit. And if you're using lead free for some reason, it won't work at all
>ou're running THT parts with traces between
You can't achieve this precision with diy tech. For home process min track is about 0.5mm and clearance 0.5mm too. 1/0.5mm is easier to achieve.

>>2691082
> solder mask prevents bridging
No it doesn’t. It’s to mask off trace areas only.
In >>2691025’s pic, it was clearly wave soldered first and *then* masked. Then run through again. Why? In cases where you want higher current carrying capacity, and a substitute for tin plate. The surface tension of molten solder only sticks to other compatible metals, not to FR2 or FR4.

>>2691137
>was clearly wave soldered first and *then* mas
Nope. I think solder mask was applied before wave and it just doest stick as well to solder

>>2691141
See these funny wave-like features UNDER the solder mask? They’re made of solder, and they are characteristics of wave soldering.

>>2691158
… cont.
I know what you fucking zoomers are thinking…
> The solder wicked it’s way there.
No, as you can see, the sinclair logo has been wave soldered even with no ingress point through the mask. Especially the second ‘i’.

>>2691141
>>2691158
… cont.
I know what you fucking zoomers are thinking…
> The solder wicked its way there via open pads
No, as you can see, the sinclair logo has been wave soldered even with no ingress point through the mask. Especially the second ‘i’.

>>2691162
>>2691158
I think this is just shitty HASL, that was applied before solder mask.
chemical plating is smoother, and prob wont wrinkle.
Still, fact is that solder mask helps during wave soldering. Maybe you can wave-solder bare FR4 or FR2, but it would be painful.

>>2691105
>you could have applied it just in suspect places
Yeah but it would look bad. I’d be more partial to doing that if I had a transparent mask to apply.
>lead free
The only lead-free I’ll ever use is the stuff with bismuth in it. Flows beautifully and melts easily. Kinda weak though, leaded is still my go-to.
>You can't achieve this precision with diy tech
I absolutely can. Once my beam width compensation is tuned in properly, I’ll definitely be able to get 0.25mm traces between THT pads.

>>2691137
I mean bridges between pads and nearby traces. Especially important when soldering with paste. I often end up running a trace between the thermal pad and leads of a D2PAK, which is a case where I wouldn’t want that paste spillover to cause shorting to a trace.

>>2691158
I always thought this was rippling caused by delamination of the mask over time, I only see it on old boards. Though I could well be wrong.

>>2691162
Isn’t this just lumpy here because there’s copper where the letters are and not anywhere else? Doesn’t even imply it’s soldered or plated, though by colour I’d guess it’s plated.

>>2691232
>The only lead-free I’ll ever use is the stuff with bismuth in it. Flows beautifully and melts easily. Kinda weak though, leaded is still my go-to.
Hm, bismuth solder is probably better for FR2 than leaded

>>2691209
> hasl
>>2691232
> lumpy
Whether it was a single sided horizontal hasl process without the hot air or the functionally identical wave soldering process, the point is that molten solder and flux was applied before the mask, and there is little fear of solder bridges. It’s common in PSUs (many of which, el cheapos, don’t have mask on FR2) and you can even restrict it to specific ares by controlling the wave and the angle of the board. It’s not delamination, I invite you to find such a board and examine it.
Those wavy patterns are caused by the re-melt from the next process underneath the cured solder mask. Anyway, it’s very common.

>>2691232
>Once my beam width compensation is tuned in properly,
bruh that's not DIY, that's "why the fuck aren't you making 6 figs"

>>2691268
Too bad I ran out of it. I’d buy more, but LCSC no longer sells any soldering consumables.

>>2691275
What process are they even doing though? You can hardly apply a thin film or squeeze a layer of UV cure solder mask onto a board that has leads sticking out of it. Let alone cure it with focus. Do they spray the shit on? Spin-coat?

>>2691276
$40 diode laser bolted onto an ender 3. The beam width is like 0.2mm. Still way better than fucking with transparencies, I highly recommend it if you’re too cheap for a pulsed laser (YAG or fibre). With any luck I’ll have a refurbished snapmaker mini within a week, which should be far more rigid for automated drilling operations. I imagine the laser is better too, but I’m not sure on that.

>>2691312
sounds expensive and tedious. i'll stick with deadbugging for now thx

>>2691158
>>2691275
Ah I see. They haven't soldered underneath the mask, but they have chemically tin-plated underneath it. Then they've soldered after the mask has been placed, which reflowed the tin plating, causing the ripples. Maybe someone already said that and I'm being retarded though. Looks like it's partially due to solder wicking underneath the mask from the pads, since there's more ripples near pads than away from them.

Tin plating before soldering is important for wave soldering, since there's no flux to help the solder stick. But I still don't see why they had to put the mask on after plating the board with tin, maybe it's about corrosion resistance and ingress beneath the mask.

>>2691334
>expensive
Eh, if you already own a 3D printer for other reasons it's only another $40. 3D printing is a great augmentation to electronics as it allows you to make custom enclosures and fixtures and such for electronics. In addition to cases, I printed myself a resistor lead bending tool for a hundredth the price charged by my local merchants, and printed an IC lead bending tool so they snap nicely into breadboards and PCBs.
>tedious
Well I did spend dozens of hours writing bash and python to get the whole thing working. Not that I wouldn't share my code for anyone else trying to do the same thing. Ideally I'd make it a plugin for KiCAD instead of a seperate script. And ideally I'd bypass Lightburn and Inkscape since they're sources of pain. But I'm too much of a potato coder to write an offset fill gcode generator, to say nothing of combining adding and subtracting vector shapes. Barely got flattening beziers done myself and that's using an existing python library.
>deadbug
A pain in the ass for fine SMD packages, but nice for analogue and RF stuff.

>>2691335
>Tin plating before soldering is important for wave soldering, since there's no flux to help the solder stick.
Boards are sprayed with flux before soldering

Been having trouble with my car's stereo, Bluetooth audio sounds like shit with lots of artifacting and random skips. I want to record the raw output by connecting a wire directly from the head unit output to the microphone input of my laptop. What size resistor should I use between a head unit intended to drive 4ohm speakers and the mic input on laptop pc?

>>2691359
Tldr; you probably want a voltage divider.
> head output
You mean the speaker output? With luck you have a “line out” jack somewhere.
> laptop mic
This is probably wants an electret mike element and will probably give it a DC bias voltage. You don’t want that.

So, two resistors for the voltage divider and a capacitor to kill the DC bias voltage.

I imagine the output voltage will be 12v pp, the mic input should be < 1v. The resistor values can be pretty high as the current needs to be bugger all, < 1mA.

>>2691335
> reflowed the tin plating
Tin plating is on the order of atoms thick, like gold plating. It can’t reflow.
Instead, they sprayed it with flux and dipped/floated it in a vat of molten solder.
Then they applied the solder mask, and the components.
Then they wave soldered it which cause the ripples/wrinkes.
There may have been some extra wicking of solder from solder mask exposed pads during the wave soldering process, but not necessarily so.

>>2691367
>the mic input should be < 1v
Pretty sure it should be <10mV, mic inputs have a lot of gain already.

>>2691371
Ok that explains the symptoms we see.
But why do they do it that way? Higher current carrying capability for the traces?

>>2691376
> why solder bath?
It replaces the plating process with a process you already have.it’s also usually cheaper. Who wants a whole separate plating line? The current/heat capacity are added bonuses, it’s sometimes done intentionally on high power devices. See picrel for a similar approach.

>>2691404
My question is why tin the board BEFORE masking it?

i have a few dumb noob quesions

would trying to "build" a solder pot by using the concave underside of a coke can and putting it over a tea light work? I just want to strip/tin very thin enameled wire

now that i think about it, would setting wire i want to strip in molten solder work? the solder would obviously get all full of dross but then just wiping the wire clean and applying flux should make it ready to solder, right? would that be easier than using shitty wire strippers?

unrelated to the last two but is it possible to repair these dumb connectors in any meaningful way? i have tons of fine enameled wire but not the gawdliek soldering skills to attach 16 of them spaced 0.5mm apart.

>>2691431
>would trying to "build" a solder pot by using the concave underside of a coke can and putting it over a tea light work?
I don't think tea light have the necessary heating capacity to do so, but give it a try, I don't think solder is going to melt. Also note that solder wire have flux "built into" it, so your tin bath will have a lot of burnt flux in it.
>the solder would obviously get all full of dross
Yes, also it may not even work depending on the coatin of the wire. I'd recommend the classical mechanical wire strippers or picrel thermal wire stripper which you can diy yourself as well. It does what you want and when you stripped the wires you can just dip them into your diy molten tin bath
> is it possible to repair these dumb connectors in any meaningful way?
If the housing is damaged and you can't close them, then I don't think so. Had one of these break in my old laptop and only managed to "repair" it by permanently gluing the little lid shut. If you just want to reuse them/reflow them, than use a heating plate and a heat gun and if you are careful, you can reflow it without melting the plastic

>>2691431
Remove the shitty connector with hot air and solder a new connector by drag soldering with an iron.

>>2691424
> why tin before masking
Because, as said earlier, solder already doesn’t stick to fr4, it’s primarily for areas that have traces on them. There are possibly other benefits (real or imagined)

Any idea what the generic name of this type of connector is? Results of "PS4 Slim 4 pin power connector cuh-16p1a" are all cables costing upwards of 20 dollars for me.

>>2691611
Looks like a JST connector, but can't tell for sure.

>>2691367
>You mean the speaker output?
yes, the actual wire going from the head unit to a speaker
>Laptop mic
I suppose I could drag my desktop out to the garage and use the line-in port
>>2691376

So would a 1k ohm resistor be a safe place to start?

>>2691611
kill yourself retard

>>2691625
nyooo :3

>>2691622
> 1k to start?
As a general rule, you want to start on the safe side, so 1 meg. Again, that probably won’t reduce the voltage, only the current.

>>2691622
>1k ohm resistor be a safe place to start?

best place to start, and to end, is a 10K - 100K pot or trimmer.
doesnt matter if it's linear or log taper.
start at min volume and crank it up until you're just below distortion level.

>>2691431
Stripping wires is better done by molten salt pot. I think a hydroxide is what is used most often.

>>2691622
I'd use a 100Ω-100kΩ voltage divider to divide the voltage by a factor of 1000. And also add antiparallel diodes (before the high-pass cap) in order to clip any spikes. Pic related.

As the other guy says you can use a pot (maybe a multiturn trimpot) to get the gain correct more easily.

>>2691737
>molten salt pot.
dont i need to reach something like 1400 C for that

>>2691737
This is a good general purpose input matcher.
The only note I’d add is to use shielded cable on the output to the PC side since low voltages can pick up hum/noise.

>>2691827
320C for sodium hydroxide, so probably doable in a solder pot, assuming the pot itself won't rot from it.

>>2691837
>low voltages can pick up hum/noise
High impedances can, but with the 100Ω parallel resistor there I don't think it's a big concern.

>>2691933
a candle flame is around 1000 at the base so why wouldnt it melt solder

>>2691942
A tea light can only output ~30W of power. That's fine for a small soldering tip, but I suspect it's not enough to keep a surface area that's significantly larger from dissipating so much heat that it doesn't get hot enough. Might work ok with insulation on the bottom, though it could still take a long time to heat up enough to melt. Thinking about how long it takes my 70W soldering station to melt a blob of solder inside an XT60, I suspect 30W will take like half an hour to get a solder pot up to temp. I'd want a few hundred watts minimum.

>>2691944
I had an 8w iron and it took seconds to heat up. my 40w iron takes about five minutes. there's more to it than sheer wattage and wattage of a flame is not easily measurable (or even meaningful in vacuum) anyway

>>2691945
>there's more to it than sheer wattage
My 70W iron is a temperature controlled iron with a cartridge tip, as opposed to an open-loop or NTC iron that relies on thermal delay/resistance for regulation. It's going to be nearly as fast as you can possibly make a 70W iron, and of the same thermal feedback design as a decent solder pot. It puts out close to the full 70W when powering through a massive connector, I'd imagine no more than 20% of that will be lost befoer going into the joint. Any 30W iron is simply never going to be as fast as this 70W iron for heating up a given amount of solder, because the heat capacity and latent heat of fusion of the workpiece define the hard limits for speed. Maybe if the 70W iron was only putting 25% of its power in would a 30W iron putting over 80% of its power in be able to keep up. Your 8W iron only heats up quickly because there's less thermal mass to heat up, which doesn't apply to a solder pot where that thermal mass is independant of the heater thermal mass.

For example, if you have 400g of 60/40 solder, that means:
>molar mass ≈ 170g/mol
>heat capacity ≈ 27J/(K•mol) = 0.16J/(K•g)
>enthalpy of fusion ≈ 5700J/mol = 33J/g

>mass = 400g
>base temperature = 25°C
>final temperature = 250°C
>change in temperature = 225°C
>thermal energy = 0.16*225*400 = 14400J
>melting energy = 33*400 = 13200J
>total energy = 27600J
>power = 30W
>time = 27600/30 = 920s = 15 minutes

So it's twice as good as the half hour I estimated as a best case scenario. That assumes you get 100% of the energy from the tea light, and lose none from the large surface area of the solder pot. For an open flame, doubling that is certainly sensible.

FYI the 400g value comes from this small solder pot's listing I found:
https://www.baskiville.co.nz/products/category/.NZ.-solder-pots-spares/QUI1004C--quick-solder-pot-lead-free-100-4c
It uses a 200W heater and closed-loop temperature feedback, and I don't imagine it melts in less than a few minutes.

>>2691988
tl;dr
Brevity is the soul of wit.

i want to build a constant current programmable load that can handle 4.2V input at a peak 35A discharge. the usual way is to do this with a closed loop BJT or linear rated MOSFET. this requires a shit ton of heatsinking. are there any clever alternatives that can get around needing to heatsink 150W?

>>2692070
a heatsink + fan

>>2692135
lmao
>>2692070
Do water cooling with a swimming pool pump and a series of old car radiators inside of a wind tunnel.

>>2692070
You don’t need to shed the entire 150w with a mosfet.
Shed the bulk with a ceramic space heater in parallel with your programmable load which will make up the difference.

>>2692144
in parallel? how would the control loop work? or maybe i'm misunderstanding you.

>>2692135
>>2692140
i've heard of some people building a boost converter and then feeding it into mains. like this https://www.farnell.com/datasheets/1907679.pdf

but it seems improbably and also extremely prone to blowing up and killing me. just wondering if there's any other "good ideas" that might actually be feasible for these voltage/power levels.

>>2692163
>>2692144
oh wait never mind, i get it now. that seems like a viable option but still very challenging since i'm seeking constant current over like 2.5V to 4.2V.

>>2691997
Can't short-cut the math, sorry flunko. Have fun waiting half an hour for your tea light solder pot to melt.

>>2692070
Make a boost converter that feeds a large 12V incandescent lamp, like a car headlamp bulb.
Connect this load between the positive rail and the boost output in order to get zero volts at zero duty cycle.

>>2692242
>Can't short-cut the math
blowtorch + crucible

Is it safe to operate voltages greater than the supply voltage of an op-amp?
e.g. The op-amp is powered at 12V, but the inputs go as high as 24V

>>2692259
Not real op-amps, no.

>>2692242
>Connect this load between the positive rail and the boost output in order to get zero volts at zero duty cycle.

i'm not quite understanding this.

>>2692259
Not generally, though there are some op-amps designed for it. Generally you can sense higher voltages by way of resistive dividers, see the B6AC balance charger schematic for an example.

>>2692331
Look up a schematic for an inverting boost converter, but since these usually have high-side FETs you’ll need to invert the whole thing. Basically, instead of the filter cap and incandescent bulb being tied to 0V, they’re tied to V+. That way the minimum voltage across the bulb is 0V, compared to a normal boost that can’t go below its input voltage.

>>2692242
>Can't short-cut the math,
except you did by not taking into account the materials used, the shapes and thickness of the objects and resultant heat retention, or that an Xw candle flame is not the same "watts" as your soldering iron (your iron is pulling that many watts of electricity from the wall, not outputting that much heat through combustion)

>>2692254
what if i took a big weller soldering gun tip and just molded a clay crucible around it

how likely am i to lose an eye when it explodes

>>2692394
It wouldn't get hot enough to explode. Try it and report back. lmao
I just remembered quartz halogen bulbs get hot enough to melt your fingerprints off.

>>2692399
normal incandescents get hot enough to give severe enough burns the skin grows back smooth too

probably easier to just wear gloves tho

>>2692388
>except you did by not taking into account ...
I calculated a best case scenario through simple energy equivalence. The hint was where I wrote "as a best case scenario".
>your iron is pulling that many watts of electricity from the wall
Which all turns into heat. There's no getting away from it, all that power becomes heat one way or another, the majority being in the tip. See where I wrote "I'd imagine no more than 20% of that will be lost befoer going into the joint". That's the South African spelling, probably. Usually a 70W iron is rated as 70W at the tip anyhow, the losses in the PSU aren't included because it has a seperate PSU.
>an Xw candle flame is not the same "watts" as your soldering iron
I don't understand what the fuck this is supposed to mean. Power is power. I did a google search for "heat output of a tea light" and got thirty watts. This isn't the wonko land of light bulbs where people talk about "incandescent equivalent" watts. If you don't believe me, you can always subtract the enthalpies of formation of the products and reactants, and divide that by the burn time to get an average power output. Like 99% of that will be heat.

</sperg>

>>2692422
>simple energy equivalence.
but it's not equivalent. the "wattage" of an open flame and the wattage of a soldering iron refer to different things.

>>2692426
No they don't. Give me any fucking example that isn't light bulb bullshittery.

>>2692422
> Usually a 70W iron is rated as 70W at the tip anyhow
All my soldering irons plug into the mains, run continuously, and use their rated wattage. They form an equilibrium and settle on a constant temperature. That temperature is higher than the melt point of solder because as soon as you touch something it will sink the heat and lower the temperature at the tip in accordance with the specific heat capacity of the heating element. Ideally, that dip in the heat will still be enough to melt the solder. If not, move to a bigger one or use a soldering gun like that based as fuck diode gone wild guy.

I assume you’re talking about those digital usb/barrel jack irons. I have no idea how much power those use as I will never use one most likely since I have no need. But, I assume they’ve worked out a “70 W equivalent” like the light output of LED bulbs compared to incandescent.