/ohm/ - Electronics General

[Anonymous No.843077]

Previous thread:
>>836221

>I'm new to electronics, where do I get started?
There are several good books and YouTube channels that are commonly recommended for beginners and those wanting to learn more, many with advanced techniques. The best way to get involved in electronics is just to make stuff. Don't be afraid to get your hands dirty.

>Links to get started
http://pastebin.com/9UgLjyND

[Anonymous No.843098]

I want to make a single arcade stick that works with every console I own with the highest quality parts, gold leaf switches for buttons, leafed micro switches for the joy sticks. I want to make it for four players. I think the easiest way to do this with out actually wiring up directly from switches to console in a single line, I would just solder the switches to either side of the contacts on a cheapo repro version of the controller for what ever system. I did this years ago for a genesis and it worked brilliantly. My question now is mainly how can I do this and be able to easily switch between several (14 at this point) controller ports and how can I make it indefinately expandable?

[Anonymous No.843155]

I'm new to electronics so don't be aware that I might be very very wrong:
I was watching an electricity tutorial on sparkfun because I want to get started with electronics, and it says charge moves from negative to positive, however when I looked at circuits tutorials it was basically the opposite, positive to negative, what gives?
Something else, what would happen if on a circuit, instead of connecting the negative to the negative, you connected it to the beginning of the circuit?

[Anonymous No.843174]

Well, a negative charge will go from negative to positive. A positive charge will go from positive to negative. It turns out that typically charge is made out of electrons. Unfortunately when Ben Franklin chose the positive/negative convention, he chose wrong.

[Anonymous No.843178]

>>843098
Just throwing ideas around but what about a design based on this except instead of switching video ports it switches controller ports?
http://www.engadget.com/2007/03/13/how-to-make-a-solid-state-a-v-switcher/
Though there may be a part that would be more suitable than that CBT3244A.

[Anonymous No.843188]

>>843178
Might work, I needed one of those anyway since part 2 of this place is an enclosure surrounding a widescreen BVM (which I don't own as of yet) with the consoles neatly shelved along both sides.

The main problem is the fact controllers have completely disparate amounts of inputs, from 1 button plus JS to 8+2 plus JS.

Not to mention I'll still have to worry about shit like a trackball for games like Centipede, the paddle controller for VCS, and anything past 4th gen which uses analog sticks and touchpads and such which I cba to even think about.

Ideally I'd have some sort of pass through so I could used original controllers of that was happened to be needed, since not every game, particularly ones I like, needs anything beyond 8 directions and some buttons, even new releases. My issue is that I also intend to use real arcade boards (I own 5 non-JAMMA right now) and those all need separate wirings, and every console I own and intend to own (even of they just use something generic like DB-9 or USB they need a separate entry)

I'd consider just using a microcontroller to do pass through, then I could even use a digital display, but I need to tests as that could introduce milliseconds of lag, and since most of my friends and I are into fighting games and shmups that's critical.

[Anonymous No.843195]

>>843188
You could use a FPGA

[Anonymous No.843221]

>>843195
Overkill. 74 series logic will do it.

[Anonymous No.843335]

This is unrelated to his question but I've been curious how do serial connections like the genny controller register simultaneous inputs like for diags and two button attacks?

[Anonymous No.843375]

>>843335
The Megadrive's controller port does not use a serial format. But in any case, you get one bit per control. If "left" and "up" are both active, you know the player is pushing diagonally.

[Anonymous No.843480]

>>843155
They didn't know about quantum physics when electricity was discovered so they named it backwards. Circuit diagrams follow the old wrong way called convential current.

[Anonymous No.843482]

>>843155
>>843174

[Anonymous No.843828]

Is this hard to build/program?
https://youtu.be/PQicXbj5Ivs

[Anonymous No.844062]

How do you keep components on a board without them falling off / moving?

[Anonymous No.844064]

>>844062
Superglue

[Anonymous No.844066]

>>844064
So the glue won't melt or anything?

[Anonymous No.844067]

>>843828

It all depends on your skill level. For me, I would say no. It's more involved than a one-day thing, but could be accomplished in a week easily not including waiting for parts in the mail. If you're just beginning, this could be accomplished likely within one and a half to three months, depending on how much you work at it and your familiarity with electronics/code.

[Anonymous No.844070]

>>843480
They didn't know so they guessed. 50/50, guessed wrong. Doesn't actually matter anyway. And it's more convenient for multi-path circuits where you will have multiple voltage levels as power sources and ground is just a reference.

>>843155
I had trouble with this in highschool. But just don't think of anything as positive and negative. Just think of it as a certain number of volts. And definitely move beyond thinking of electricity as the positive and negative terminal of a battery because that shit will just confuse you in any kind of oscillating circuit.

When you look at a circuit diagram, everything is just relative to one common reference point, ground.

[Anonymous No.844071]

>>843828
Was this filmed in the kingdom of Bhutan?

[Anonymous No.844077]

Would this tool set be good?

I'm poor as fuck but wanna get into electronics repair as a hobby and this is well within my price range.

[Anonymous No.844085]

>>844077

Will it work? yes.

Is it good? no.

[Anonymous No.844090]

>>844077
Yeah, that's a good price even without that cheap shit iron, which is good because you'll want to throw that away and get a real one that's worth the investment, that one will be awful to use for the 2 weeks before it breaks

[Anonymous No.844095]

Where can I get a really nice electronics work bench?

[Anonymous No.844101]

>>844090
What do you recommend?

[Anonymous No.844104]

>>844101
Weller WES51 is easily the best soldering iron under 250 dollars and its usually only 80-90. Professionals use it as a workhorse for years and it holds up, as good as the best in the world for 99% of amateur/professional projects

[Anonymous No.844322]

>>844104
How is the WLC100?

[Anonymous No.844338]

>>844095
Search the EEVBlog to about benches; make one yourself.

[Anonymous No.844340]

>>844322
>WLC100

No.

[Anonymous No.844343]

>>844340
So cancel my order, and spend the extra $50 on the WES51?

[Anonymous No.844379]

>>844343

If you never used a nicer iron than that, you won't notice it, but if you use one in your life that's ~WES51 or better quality, you'll be kicking yourself for not just getting a decent quality iron. In the event that you don't follow electronics as a hobby later on in life, you'll still have instances where you'll need to solder something together and you'll still appreciate it then. I've worked with the WLC100 before in school, worked with the nicer wellers and hakkos, and some of the really expensive rework stations. Will the WLC100 work? yes. Is it enjoyable? Not really.

[Anonymous No.844383]

>>844095
Global Industrial supposedly has a lot of workbench parts designed for electronics like ESD preventing tops, wire roller holders, scope mounts, computer mounts, et cetera but good luck working out their website. It's a fucking mess. Also all the benches are blue but that's pretty standard.

[Anonymous No.844385]

Would a sandwich grill get hot enough to solidify solder paste?

[Anonymous No.844387]

are surface mount parts really going to completely push through-hole stuff off the face of the earth or is that just FUD?

[Anonymous No.844424]

>>844387

The only reason they haven't is because there still exists perfectly good automation equipment for THT parts. SMD packages are far more efficient in terms of material use (which translates to "cheaper"; obviously this alone is significant usage incentive), usually have a smaller footprint than equivalent THT parts, they're easier for automation equipment to handle, they're less wear on the fab houses' drills, and lines of them don't break up internal power/ground planes.

Obviously, there's still use for through-hole where mechanical strength is an issue, but, other than that, there's little reason for industrial manufacturers to choose a THT part when an SMD version is available.

[Anonymous No.844470]

>>844385
yes but you need a very good controller (make the grill follow the temperature curves) to not to fuckup the boards and sensitive components
also related:
http://fortyseveneffects.com/tutorial-diy-smd-soldering-with-a-frying-pan/

[Anonymous No.844602]

Guys I got this bunch of diods on amazon.
I want to make a little clock working ith the diods something pretty simple, but I want the clock and the diods (12 of them) to work with the same battery. Is there a way to know how much amp/ h the diods will take ?
All I already know about them: DC 3.0V -3.4V

[Anonymous No.844621]

>>843077
The pic make me laugh so hard
Inot my technology class was a girl who wanted to test if the soldering iron is hot
With her fingers

[Anonymous No.844636]

>>844379
Concerning the Weller, my little sponge is just covered in solder now. How do I get rid of it?

[Anonymous No.844697]

>>844602
Not according to my research.

[Anonymous No.844706]

>>844343
never used the wlc100, the wes51 compared to shitty handheld iron is such a huge difference.

[Anonymous No.844792]

>>844636
An actual sponge? Moisten it and brush as much of it off as you can. Solder shouldn't really stick to it if you keep it moist, though.
If it's metal wool: rub most of the solder off, turn the sponge inside out or w/e to expose fresh wool.

If neither works, replace the sponge.

[Anonymous No.844922]

Where can I find a NEMA 6-20R and matching cover plate? I really don't want a white receptacle with a stainless cover plate.

[Anonymous No.844925]

>>844621
I've done that before, unless you've got bizarelly damaged nerves and slow reflexes it's not like you're gonna hurt yourself

Although your post does remind me of GCSE electronics where we'd heat up pennies using the soldering irons and drop them into peoples hands to see how long it'd take them to realise they were holding onto a burning hot piece of metal

[Anonymous No.844944]

Isn't there something you're supposed to do with the ground traces in audio circuits? Every connection to ground on the board is supposed to be taken from a single junction, right? What about the power supplies? Should those be connected from one point as well or does it not matter?

[Anonymous No.844958]

>>844944
>Isn't there something you're supposed to do with the ground traces in audio circuits?
i am not an expert but,,,, the only thing I've ever heard about audio circuits that was special was that the speaker [+] and [-] connections are "normally" always floating... specifically-----the [-] speaker connection(s) is never connected to the actual electrical ground unless the instructions for your circuit tell you to do that.

I has a question about stepper motors and drives, specifically the step modes (pic related),,, the step modes in green I understand, because they are in multiples of 200/400. what are the modes in red for?
note that:
1. the device only has two bipolar output connections,,, and-
2. a normal stepper motor has 50 poles, and 2 windings that can connect both ways (50 x 2 windings x 2 directions for each winding = 200 steps/revolution). Or,
3. some stepper motors have 100 poles on the rotor and then two windings, so they are 400 steps/revolution....
4. what motors would be able to have 1000 steps per revolution? I don't get it

id ask the vendor on ebay (Longs) but their instructions are pretty bad chinglish. The drivers do work, but the hookup instructions on the website don't even work.

[Anonymous No.844977]

>>844958

Looks like there are steppers out there that operate at that condition:

http://www.orientalmotor.com/products/stepper-motors/stepper-motor-only-0-36.html

[Anonymous No.845004]

>>844958
steppers with reduction gears?

[Anonymous No.845023]

>>844385
(Replying to myself just to let other people know I've found a better way to do this)

https://www.youtube.com/watch?v=1xNSMTWhEvg

[Anonymous No.845040]

Would painting my work bench with ESD paint designed for concrete floors function the same as those ESD tops that are for industrial workbenches and costs way too much?

On a non-/ohm/ point would that paint adhere to wood acceptably or would I need to make the top concrete? I was thinking of doing that anyway but still

[Anonymous No.845052]

>>844062

If it's through hole, use tape

[Anonymous No.845054]

I've got a weird problem.

I set up an arduino connected to a relay which switches the spindle on my CNC machine on or off. The arduino is connected to the CNC computer (an old shitty one made in 2005ish with around 1GB of RAM) through a USB port. Pretty basic, right?

It's somehow interfering with at least one axis's steppers since I noticed a creaking noise when I told the arduino to switch on the spindle, and on closer inspection I noticed my Z axis creeping up despite EMC2 (machine controller program) telling me all axes were stationary and I was not running anything.

What exactly is going on here and how should I fix it? See pic related for the setup.

I have a better CNC computer on the way so would that help?

[Anonymous No.845062]

>>845054
Better pircture

[Anonymous No.845080]

>>844062
usually I solder them.

:^)

[Anonymous No.845086]

>>845080

This is a legitimate question, as you usually put the components on the top side, but the solder goes on the bottom side. So you put in a resistor, for example, and when you turn the board over to solder it it falls down.

[Anonymous No.845097]

Quick question for you guys.

I have to measure an analog voltage that could be as high as 24VDC, so I need to scale that way down to 0-5VDC so as not to fry inputs.

What's a good way to do this? I could use op-amps.

[Anonymous No.845099]

>>845086
> components on the top side, but the solder goes on the bottom side

I just don't give a fuck and put components on the solder side. Debugging is also a lot easier when you can see all the paths and components at the same time.

[Anonymous No.845101]

>>845097
You just need a voltage divider (two resistors).

[Anonymous No.845103]

>>845054

Sounds like noise is being generated on one of the parport lines. You might be able to fix it by moving the power cords away from it and/or adding an RC filter and increasing your signal hold timings.

What stepper driver are you using? Using a cheap Chinese eBay controller, I had an issue with the Z axis just being generally retarded and completely unusable when trying to step. Fixed it with an RC filter, but I still have no idea why only the Z axis was affected. Bad driver chip maybe, IDK.

[Anonymous No.845104]

>>845101
Right but isn't that wasteful?

[Anonymous No.845107]

>>845104
Wasteful how? In terms of components it certainly isn't.

In terms of electrical power the waste comes from the resistors you choose. If the two resistors have a combined total resistance of 100k you're only wasting 24v/100k = 0.24mA.

[Anonymous No.845111]

>>845103
I've been using a TB6560 for years. I thought it was one of the more well-liked drivers.

So where should I add an RC filter? I'm guessing right between the relay and the spindle?

[Anonymous No.845115]

>>845104
Yes, it is terrible

Look for something called buck converter, they're fairly cheap and very efficient.

[Anonymous No.845144]

>>845115

Don't give an answer if you aren't actually reading the initial question. A buck converter is totally and completely inapplicable here.

Unless you have some very odd current requirements for the load being supplied by the 24V you're measuring, a voltage divider is exactly what you want. Choose a set of values that will limit the voltage to no more than 5V (5:24 or ~0.208) and keep current draw to an acceptable level.

Alternately, if you need/want more precise scaling than is achievable with common resistor values, just use a potentiometer and adjust it accordingly.

Note that the higher total impedance value used, the less current is available for your device to measure with. At higher values, the measurement is more susceptible to noise. At extremely high values, the bias current of your measuring device becomes a significant error in your measurement.


Opamps are usually used to boost a signal, not attenuate it. The only exception to this might be that whatever you're measuring will be thrown off significantly by the couple hundred µA draw imposed by the divider network. There's no reason you COUDN'T use an opamp to lower a signal, it's just that they only offer disadvantages compared to a resistive divider, with the one exception of lower current drawn from the load.

[Anonymous No.845166]

>>845086
yeah yeah I know I know, I felt like shitposting and I couldn't help it. What I usually do is just feed the leads through and then bend them back toward straight so it'll be held in place. I mean, I've never given it much thought. The other two suggestions are good too if a part is being tricky.

[Anonymous No.845167]

>>845166
>>845086

Or better yet; solder the top-side such that you get the solder to flow through to the other side as well. If you need to clean up the bottom afterward, it's already held in place. This requires a decent iron to not be a pain in the ass, usually.

[Anonymous No.845213]

>>845103
The weird thing is that the wire from the spindle to its own power supply is just as close to the ribbon connecting the motor driver to its parallel port as when the spindle was connected to the relay, yet the same interference does not happen.

[Anonymous No.845219]

>>845144
What's the disadvantage of using an op amp to lower a signal?

[Anonymous No.845223]

>>845111

The TB6560 itself is reliable.

However, the no-name Chinese boards you can find them on are not. Like I said, had I any sort of standards, I would have sent mine back because it was essentially useless in its default state. But I have more time than money, so I tore out the optocouplers (which were too slow for this application and the isolation was done improperly anyway, defeating the purpose in the first place) and added a filter to the Z-axis chip's step input pin.

Inspecting the board, I could not find a single damn thing that would have caused the Z to behave differently (all the axis are routed and populated effectively identically), yet it didn't work at all before I added the filter.

>I'm guessing right between the relay and the spindle?

No, you're trying to filter the signal to the chip, not the power line to the motor. You want it either between the driver board's z-axis step input and the optocoupler (essentially immediately after the cord) or right before the chip's step clock pin.

>>845213

Is one of the wires shielded and grounded and the other not? Also, relays themselves generate a bit of RF noise when switching. Might be it, hard to say without testing stuff.

[Anonymous No.845224]

>>845219
Why would you use an op-amp when it's completely unnecessary? You sound like someone who's only read the op-amp chapter of an electronics book and is scared to do anything without one.

[Anonymous No.845226]

>>845219
>What's the disadvantage of using an op amp to lower a signal?

A divider is closer to the ideal than an opamp. It responds almost instantly to changes in voltage (opamps have a slew rate), is more linear, and are simpler to implement.

Modern CMOS opamps are generally very good in terms of performance in most cases, so these differences are typically negligible. However, they don't offer any advantage over a resistor ladder unless you want to do something odd like change the gain on-the-fly or have current limitations in the range of microamps.

[Anonymous No.845246]

>>845223
I don't think it's just the Z axis that is affected.

When I checked a piece I cut earlier this morning with the relayed spindle, it had signs of one of the axes creeping as well since the surfacing cut was more like a staircase showing that at the z axis and at least one other was creeping.

How would you check the relay for RF noise?

Here's another interesting thing: The relay causes the Z axis to creep when it is on but if it is attached to the machine and powered off then no creep happens.

[Anonymous No.845251]

>>845054
Are you driving the relay properly with a transistor and snubber diode, or did you connect the coil directly to an arduino IO pin?

Have you tried adding a larger decoupling capacitor to the arduino or powering it from not the same computer that's controlling the CNC through the parallel port?

How is the code to control the relay through the arduino integrated into the regular CNC parallel port control? An old computer like that won't handle multitasking that well and could start putting data on the parallel port in badly timed bursts if there's a higher priority task.

[Anonymous No.845330]

>>844977
>Looks like there are steppers out there that operate at that condition:
no, because those 1000-step motors use a 5-wire "Y" connection. they have 5 windings, not 2:
http://www.orientalmotor.com/technology/articles/article-new-pentagon-bipolar-driver.html
the stepper driver in OP would not work with those motors at all...

>>845004
>steppers with reduction gears?
that would not matter.
in a typical 1.8° step motor, you have 200 steps to complete 1 revolution of the motor.
if you want to microstep further, you need the microstep division to be symmetrical over the real-actual step rate (of 200 steps)
so you would microstep 400, or 800, or 1600 steps. So that there was equal microstep subdivisions both before and after each of the actual-200-real-steps
you can't take a 200-step motor and symmetrically microstep it over 1000 intervals per turn. because there is no way to create 1000 equally-spaced positions with only 2 bi-directional windings.

I got these drivers (Longs) off ebay but the company has its own website. Its possible they have some kind of special motor lurking on their website but I looked around there and all the ones I saw looked pretty typical (200 steps)

[Anonymous No.845516]

I have a project that involves an arduino, a light sensor for the arduino, a camera for the arduino, and a wifi shield for the arduino to connect to the internet. And a battery for the arduino.

Let's say I want to replicate the project multiple times. Is there a way to copy the entire thing onto multiple boards, without needing a new arduino for every board? Is there a cost efficient way to do this?

I'm making a security camera for the inside of my locker at school. The fall semester has a higher break in rate than any other semester and I want to protect my stuff while I'm at the gym. If they end up stealing my arduino I want to be able to replace it easily and cheaply.

[Anonymous No.845524]

>>845516
By building it from discreet components and an AVR in the first place instead of shelling out the ass for a jewish devboard. The chinks make them for $5 if you're incapable of that.

[Anonymous No.845526]

>>845251
The arduino is connected directly to the relay coil for now.

The program controlling the arduino is entirely separate from the CNC machine controller program. I had it open in a different console while the CNC controller is running.

Do you think adding the transistor and snubber diode would help?

[Anonymous No.845528]

>>845526
Just to be clear, the relay is not a standalone relay.

It's a board, specifically pic related.

[Anonymous No.845531]

>>845516
>Let's say I want to replicate the project multiple times. Is there a way to copy the entire thing onto multiple boards, without needing a new arduino for every board?
uhhh, not really,,,,
>If they end up stealing my arduino I want to be able to replace it easily and cheaply.
buy your arduinos on aliexpress -- pic related
for that matter, look for the other parts there too

[Anonymous No.845534]

>>844602
Every diode has a current rating, a nominal voltage rating, and sometimes they do the math for you and tell you how much wattage they are. If you don't know it, just look up the part number with the manufacturer, or hook one of them up and test it with a Fluke,

[Anonymous No.845537]

>>845531
God bless your soul
Merry Christmas

[Anonymous No.845606]

>>845531
amazing price but the chipset is not removable

[Anonymous No.845633]

>>844077
>well within my price range.

>>844104
recommends a soldering iron that is 5x the price of the entire set.

There is quite some stuff in that set that you might not need. I would get a bitset and small screwdrivers of opening devices, a second hand soldering iron, any will do for now, a wire cuter and a stanley knife. all of this can be had for cheap if you try.

[Anonymous No.845648]

>>845330

Then what are you asking?

[Anonymous No.845650]

>>845633

>5x the price of the entire set
http://www.amazon.com/Weller-WES51-Analog-Soldering-Station/dp/B000BRC2XU

What is 3.1

But really what he should do is just get that set and be done with it; he's going to need to save some money for components. Once he decides that he likes this stuff, he should spend more on better equipment.

[Anonymous No.845655]

You guys are gurus and helped me out before. I've got this illuminated switch, 5 terminals. Outside terminals are power to the switch light, bottom 3 are 2 positive and one negative. The switch is always illuminated, I want the switch to only be illuminated when it's turned on. I've got any ideas? I think I've got it figured out. Power leaving the switch section runs to positive on the light and then terminates to ground.

[Anonymous No.845705]

>>845606
>amazing price but the chipset is not removable
who cares? it takes like one minute to connect it to a PC and upload the sketch to it
or there's ones with DIPs+sockets in there too. but they cost more

>>845648
>Then what are you asking?
I was trying to figure out what the base-5 modes were for.... apparently it is just a slightly-smoother way to run a normal bipolar motor. Or, to get a set of intervals that is not directly based on the actual 200 steps/revolution.
when you switch from normal driver mode (200 steps) to 400 step, it divides each actual step into two smaller current steps
when you switch from normal driver mode to 1000 steps, it divides the pulse current change into five intervals.

[Anonymous No.845708]

>>845086
>This is a legitimate question, as you usually put the components on the top side, but the solder goes on the bottom side.
the original reason was because mass-produced PCB's were bath soldered.

if you are using a regular soldering iron then it may not matter really.
if you are using board with one-sided copper-plated pads, having the pads on the opposite side of the board does help resist the pads from pulling off

[Anonymous No.845716]

>>845705

Ah, okay, so something along the lines of this:

http://www.zaber.com/applications/?tab=Technical%20Articles&article=microstepping%20tutorial

?

[Anonymous No.845723]

>>845655

wire it like so. if the switch works backwards (off in the on position) then wire the ''12V in'' to the green wire instead.
this assumes the lamp is rated for the same voltage that you're switching. if it's a 12V lamp and you're switching 120V, then it's gonna blow the lamp.

[Anonymous No.845724]

>>845655

wire it like so. if the switch works backwards (off in the on position) then wire the ''12V in'' to the green wire instead.
this assumes the lamp is rated for the same voltage that you're switching. if it's a 12V lamp and you're switching 120V, then it's gonna blow the lamp.

[Anonymous No.845730]

>>845724
It works! Thank you.

[Anonymous No.845758]

I've been working on a pcb for this VFD for several hours, and I just realized I can't solder the leads to the copper pads, the tin just doesn't sticks to it, I tried scratching them with sandpaper, but still... Is there some way to solder the leads to the pads?

I can only think of conductive glue.

[Anonymous No.845770]

>>845758

those are obviously solder pads, so solder has to stick. if you're using lead-free solder, switch to leaded. otherwise, you need to gently scrape off any oxidation or anodizing with a tiny grinding wheel on a dremel. or a small file if you have a lot of patience. you just need a tiny spot where you can make contact with the underlying metal.

[Anonymous No.845784]

>tried my hand at soldering SMD components
>toner transfer was fine, tracks were good enough
>soldering the SMD components was easy and good enough, considering it was my first time ever
>gotta solder the LEDs now
>botch two out of eight
>should have soldered them on the other side

Well, it didn't turn out so bad. It works.

[Anonymous No.845969]

>>845770
The problem aren't the pads, but the leads of the display, which seem to be made of some metal which doesn't gets soaked by the tin at all.

[Anonymous No.845992]

>>845969
Well, that's certainly possible, if you "converted" it to an SMD component by cutting the solder-covered part of the leads off.

[Anonymous No.846300]

So everything on my automatic lifejacket signal circuit works except I realized that Attiny85 doesn't start interrupts using a +5v signal, it must be pulled to 0v. How would I change this circuit to get achieve this? As stands, when the probes are connected, a +5v is leaving the emitter when the probes are connected. I know I need to use a pull up resistor but i'm not sure how.

[Anonymous No.846317]

>>846300
Oh wait, I thibk I figured it out. I can connect another transistors base to the others emitter and just comnect the chips pin on the seconds transistors emitter and connect the collector to ground.

[Anonymous No.846365]

Why isn't this circuit working? It's supposed to produce a square wave, I double checked the connections, I've redone the circuit three times with two different 741 ICs. I'm using 0 volts as the negative input, I recall using a similar circuit (if not the same) with an LM324 to make a buzzer buzz and it worked flawlessly (even with no negative voltage). Halp.

I'm going to try with the LM324 again, but I still don't know why it doesn't works with 741s.

[Anonymous No.846371]

>>846365
I tried with the 324 with no results, I've been googling for several hours looking for the circuit which made it work the first time.
I tried making my own changes and I got a signal, but it's nothing like a square wave.

[Anonymous No.846403]

Cant get these two wires in my ceiling fan to stay connected. One's solid core coming from the house and the other is strand from the fan. The motion of the ceiling keeps knocking this one wire connection loose every few months, is there a specific way to join these types of wire. The fan is doesn't appear to be wobbling. I've tried the twist kind and solder and tape.

[Anonymous No.846409]

>>846403

Solder didn't work? Did you do it right? How about wire nuts? Post pictures? We meddle with electronics but we aren't your personal electrician? Everything is a question?

[Anonymous No.846438]

>>846365
the comparator/opamp's negative supply needs to be well below the voltage r1 is attached to. It needs to have a negative supply so that its output can swing negative to discharge the capacitor for the second half of the cycle.

alternately, replace R1 with two resistors (of 2*R1 ohms) one going to V+ and one going to V-, making a voltage divider -> virtual ground at the midpoint of your supply. If this draws too much current use another opamp as a buffer creating your virtual ground.

[Anonymous No.846449]

is kicad shit? every time I've tried to use it for anything, none of the components that I can buy in real life are in the libraries. do you just need to make all your own symbols for everything or what?

Ive never used a pcb/schematic program before. I find it odd that it would be this difficult. I tried another free program (can't recall which one) and it had the same issue.

all I want is to lay out some 8-pin DIP ICs and some power transistors on a board.... if it just had generic "component shapes" that would be enough, but there is nothing like that.

[Anonymous No.846451]

Hey guise,
I recently got this "solder-less" wiring for my guitar from EMG. One of my pickups are an older model.It still has wires to be solder on. Since i have to fucking solder anyways, what are my options so i can make this wiring diagram work?

[Anonymous No.846452]

Btw, this is the bus i have for my set-up.
double bumpp

[Anonymous No.846458]

>>846365
>>846438
Heres that virtual ground he was talking about. this circuit worked in the simulation. To make a buffer just make the virtual ground attached to negative of another op amp and tie positive and the output together.

[Anonymous No.846459]

>>846458
forgot image

[Anonymous No.846461]

>>845758
What I've found to work on both copper and aluminum solder joints that are oxidized or otherwise uncooperative is to coat them in flux, scratch the surface a bit with the flux on, then hear the whole pad with the iron until the flux starts to burn off even where not in contact with the iron. Then just drop the solder on as needed u're gtg

[Anonymous No.846465]

>>846451
>>846452
I don't understand the question. You have the diagram right there.

[Anonymous No.846467]

> I'm going to try with the LM324 again, but I still don't know why it doesn't works with 741s.

324's are specifically designed to work from single-ended supplies. 741's are not.

>>846459

that circuit is completely whack, like someone just threw in extra components here and there for no reason. here is a real artificial ground circuit for future reference.

[Anonymous No.846468]

>>846451

you get a 3-pin header from someplace, solder it to the wires on your pickup, then use some correction fluid to mark a dot showing polarity. also mark the female header from the kit with a matching dot. isolate the solder joints with heat shrink or hot glue.

[Anonymous No.846544]

>>846467
The circuit is basically the same as your suggestion. It's just missing the buffer, which isn't really needed.
The component values are bad, though, and you can actually achieve the same result by adding one single resistor. Pic related.

[Anonymous No.846545]

>>845655
how have you got it wired to stay illuminated??

[Anonymous No.846547]

>>846449

Do you realize how many components there are out there? Spoiler: there's a lot. So many that most circuit design software packages won't spend time making footprints and symbols for the majority of them. Footprint generation is automated in some softwares, but AFAIK not in KiCAD (e.g. define number of pins in a DIP package and include some other information, creates footprints for you). Once you do it a couple times you won't think twice about it, it just takes practice to move quickly through symbol and footprint generation. Save all footprints and symbols to a new library so you have them for future use.

[Anonymous No.846590]

I've never soldered before, how much should I spend on a soldering iron?
For arduino/raspberry pi projects.

[Anonymous No.846592]

>>845528
speaking of those little relay boards, how much current can you put through them before they asplode?

I had a machine with a 120vAC heating element that was drawing ~8 amps, and wanted to automate it with tarduino... but I wondered about the relay catching on fire switching ~8 amps. The relay has its own rating and the screw terminals have their own rating but what I wonder about is the PCB traces...???

During the build process I switched to a 240vAC heating element, but running it off 120vAC. This cuts the current from 5.2 amps/1200 watts to 2.6 amps/600 watts, which is enough to work... I've tested it and the relay or any of the wiring doesnt appear to get warm so I think its good as it is.

------

Also: where can I get a ~60mm fan that can withstand 140° - 150°F? My heater setup could benefit from some internal air circulation but all the fans I've ever seen were plastic.
This machine is basically a closed sheet metal box with a thermostat-controlled heater, where the top side is used as a hot (warm) plate. The fan would be placed inside, and would have to live in that ~140°F air.

[Anonymous No.846610]

>>846468
holy fuck,
thanks!

[Anonymous No.846618]

>>846592

there exist tables and calculators on the tubes telling you how much current a PCB trace of a given width can take, usually for the 2 most common ''weights'' of copper. if you dont know the weight of your copper, assume you have the 1oz.

> where can I get a ~60mm fan that can withstand 140° - 150°F?

thrift store or curbside microwave ovens, regular ovens or toaster ovens with a ''rotisserie'' setting, space heaters. these all tend to be metal-bladed except for the microwave ones. oh, and some refrigerators have nice metal fans to help evaporate the defrost water.

[Anonymous No.846622]

>>846592

and i'm guessing the purpose of this box is to kill bedbugs. i just happened to run across some brand-new bathroom-floor heaters for a pittance, so i might try my hand at making a heated box. i was thinking wood, but now that you mention it, an old metal trunk would be so much lighter.

[Anonymous No.846660]

How can you tell if a scavanged electronic part is still working? Is testing the primary function (capacitance for capacitors, resistance for resistors, etc) the only way? I've got this capacitor that seems pretty worn out but it's capacitance is in the range.

[Anonymous No.846662]

>>846590
50 if you plan on soldering a lot, 100+ if you're going to make it an extensive hobby

[Anonymous No.846664]

>>846660
Check the capacitance, make sure it is not bulging, and check the internal resistance using one of these. http://www.amazon.com/Eathtek-Digital-Capacitor-Internal-Resistance/dp/B00MUK2IEO

If the ESR isn't reading around the correct value, then the cap is bad or will go bad soon.

[Anonymous No.846695]

>>846467
that circuit is exactly what i described as the buffer in >>846458

How can you not see my circuit is basically the original circuit, with the added voltage divider and the cap to ground.

[Anonymous No.846698]

>>846409
It worked for a weeks (I'm no master solderer and had covered it in electrical tape) and I read doing research that solder isn't really a good solution with moving stuff. Had a wire nut on before which worked much longer but then it came loose and the light turned off and on intermittently. I was wondering if there was a specific type of wire nut to use for this application. I also am thinking about moving the wires and taping them to the brace. The House wire is copper the strand looks like aluminum.

[Anonymous No.846719]

>>846698
Normally a wirenut should do it. The way I always do stranded to solid is cutting a good amount of jacket off the stranded wire, about twice the length of the wire nut, then i wrap it around the solid wire clockwise looking down at the wire, so it gets tighter as you screw on the wire nut. Also both the end of the stranded and solid should meet, dont have one longer than the other. Then i just grasp them firmly and tighten the nut until it wont go anymore. This could also be an issue of not using the right size wirenut. You might have to go smaller.

[Anonymous No.846727]

What purpose does the metal part of voltage regulators and transistors have?

[Anonymous No.846732]

>>846727
heatsink

[Anonymous No.846741]

>>846727

Heatsink tab, and some also connect it interally to source or drain.

[Anonymous No.846764]

>>845086
Stick component through, bend one lead, solder the other lead, heat the solder and push it through a bit more if it wasn't quite all the way in, unbend the other lead and solder it.

That's what I do

[Anonymous No.846771]

>>846592
Why not switch it through multiple relays to spread the load?

cascade failure

[Anonymous No.846776]

>>846698
Copper-to-aluminum is hard because they have different coëfficients of expansion but it's unlikely that stranded wire is aluminum, it's probably plated copper. Does solder wet it ok?

If it *is* aluminum you might need a ferrule or terminal block that is designed for aluminum-copper connections.

Running the stranded wire through a clamp or taping it down so the vibration/flexing doesn't get to the wire nut seems like a good idea to me.

[Anonymous No.846791]

How important are ESD presentation measures with SMD IC components? Also how the heck do you keep these things still?

[Anonymous No.846815]

>>846622
>and i'm guessing the purpose of this box is to kill bedbugs.
no, it's a hot plate setup for making tread rubber for bicycle tires. I'm making bicycle tires.
I decided to convert all the electrical machines I built to arduino control so that they would be semi-automated and I wouldn't have to stand there and flip the switches at the right times.

>>846618
>thrift store or curbside microwave ovens, regular ovens or toaster ovens with a ''rotisserie'' setting, space heaters.
someone else advised me to check spec sheets and I found some that I'm going to try.
There's some general 12v dc fans that are plastic/frp but are still rated for use up to 150° - 160°F, and this use won't get over 140°F.
If they fail, I *can* attach a long shaft to a fan motor so that only the fan rotor itself is inside the box. Imma hope the plastic works tho.

[Anonymous No.846818]

>>846771
>Why not switch it through multiple relays to spread the load?
>cascade failure
I thought of using two relays in parallel. It would be similar to the practice of "stacking chips".
With the 240v heater it isn't going to be necessary really.... and the heating element is rated for up to 1700°F. At 140°F it should last forever.

[Anonymous No.847006]

Probably a dumb question, but how do i figure out which pin on triac corresponds to one on schematics ?

[Anonymous No.847012]

>>847006
Dowload the datasheet of your TRIAC. It'll tell you what pin is what.

[Anonymous No.847014]

>>846791
Super glue

[Anonymous No.847050]

Ok so, I'm stil trying to make this led panel. It has to work with battery. And I made a very good looking schem. Could you guys tell me, will it glow or blow ?

[Anonymous No.847058]

>>847050
Oh I forgot the formula of the resistances :
(18V - 3.4V x 4)/ 0.02 A = 220 ohms.
Am I right ?

[Anonymous No.847084]

>>847050
>>847058
seems fine.
another thing to check is the power dissipated by the resistor, multiply voltage drop by current, (18-(3.4*4)) * 0.02 = 0.088W
typical through-hole resistor is 1/4W so you are well within limits but its useful to know for high power LEDs or maybe smd resistors.

[Anonymous No.847093]

One of the main capacitors in my PSU blew up and I'm gonna have to change it. I have some experience soldering and replacing parts but never worked with devices that use more than 50V.

What are the main precautions I should take repairing these devices?

On a side note, I wanna know why it blew up. The night before, there was a thunderstorm that took down several electric posts, pulling the main wires from some houses. In my case, only the ground wire was disconnected and according to my brother, the mains voltage measured with a multimeter was going crazy ranging from 40V to 200V. It blew some of our lights, the refrigerator and my PSU but the PSU blew up after they repaired the damages with the posts and regulated back the mains to 120V.

Why would the mains act all crazy? Shouldn't it be unenergized due it being not grounded?

[Anonymous No.847124]

>>846791
>How important are ESD presentation measures with SMD IC components?

If your workspace has a carpet and the humidity in your part of the world is low you should probably wear a grounding strap, but otherwise you'll be fine without any special consideration.

>Also how the heck do you keep these things still?
I like to tin one of the solder pads, then hold the component with tweezers and solder down the one corresponding lead to hold it to the board. After that make sure it's all lined up properly and do the rest.

>>847014
If you ever accidentally hit crazy glue with a soldering iron it will make the most terrible smoke I've ever experienced. A small amount in a ventilated room made my throat and eyes burn very painfully.

[Anonymous No.847132]

>>847124
super/crazy-glue is made of cyanoacrylates, so burning it likely forms hydrogen cyanide and/or a host of other very-not-good, gas-at-room-temperature organic cyanides. never use superglue on anything you're going to heat up.

[Anonymous No.847133]

>>847093
the ground is only a protection wire, no current flows through it in normal operation, that is what neutral is for.

[Anonymous No.847188]

Can excessive heat cause a potentiometer to short/open circuit? I desoldered a pot to check its value so I could order a replacement for it that can be mounted on an enclosure instead.

It's not like I need this one anymore but now turning it doesn't do alter the circuit anymore (after putting it back on ofc), guessing I burnt it out or something?

[Anonymous No.847192]

>>845224
How do I sound like that from the first post you've read of me. I simply wanted reasons, to weigh against what I would think.
>>845224
Thanks.


>noob question
Is there any way to implement logic without the use of cmos switches? The leakage current fucks up the integrator circuit I'm trying to turn on/off

[Anonymous No.847241]

>>847192
CMOS switches aren't great for digital logic. You normally use them in circuits where you need to switch some analog signal like in an ADC's sample and hold. You can do logic with any type of transistor. General purpose NPN / PNP is pretty standard. You don't need to do everything with discrete transistors though. There are ICs for every logic gate imaginable.

[Anonymous No.847242]

>>847188
Is it one of those smaller potentiometers with a lot of plastic parts? Heat can cause those to melt so the wiper isn't held against the horseshoe properly. The large ones that are nothing but metal and ceramic are pretty hard to damage with heat.

[Anonymous No.847250]

>>847241
>CMOS switches aren't great for digital logic.

...what? CMOS is the standard process for damn near everything digital.

Are you're sure you're not confusing it with NMOS (even though that's also fairly common for digital logic)?


>>847192
>Is there any way to implement logic without the use of cmos switches? The leakage current fucks up the integrator circuit I'm trying to turn on/off

What leakage? A significant portion of the appeal of CMOS is that there's almost no leakage, thanks to the insulated gates.

[Anonymous No.847256]

>>847250
He said CMOS Switch, so I assumed he was talking about something like a HCT4066. A CMOS switch is a specific circuit, not a generic term for anything you do with CMOS.

[Anonymous No.847303]

Where would a guy get started with embedded systems programming?

Not sure if I should ask this in /g/ or /diy/, choosing /diy/ first.

[Anonymous No.847313]

>>847303
Can you be more specific? Do you want to do firmware (stuff that doesn't run on top of an OS), or write software for a dev board running an OS (almost always Linux).

Arduino is popular for the first, and Raspberry pi for the second. By popular I mean that hobbyists love them, not that they're the best option, and if you do go this route try not to rely on baby tutorials for too long.

[Anonymous No.847328]

>>846791
Speaking of ESD presentation, once a component is soldered, is it okay to assume it won't be damaged by ES? Also similarly for moisture sensitive components.

[Anonymous No.847367]

I'm the anon from last week with issues with a relay controlled by my arduino interfering with the axis stepper control of my CNC machine.

I got a new computer, set up the machine controller, and plugged in the arduino to control the spindle today. There was no interference anymore. I guess it was a timing issue with my old computer.

[Anonymous No.847374]

What did you guys do to start off your weekend? I did a basic line follower. I figure it's jumpy because I'm using a comparator IC instead of regular op-amps

[Anonymous No.847383]

>>847328
no, you can still harm a motherboard without soldering anything just by touching it, thats why you always touch the case (chassis ground not earth ground, the motherboard is referenced to the chassis)

[Anonymous No.847392]

>>847383
What should I do if I don't have a case for the device yet? I do have the metal sheets that I will use to make it though. Should I just touch these periodically? For a while I've been connecting my esd mat and wristband to a large metallic object but will this be harmful to my pcb?

[Anonymous No.847447]

>>847392
You could have an antistatic mat on your desk and use a grounding strap.
Or just ignore the problem. Your chances of breaking stuff with ESD are pretty slim. Protect the connectors with zeners or whatever and the chances are even slimmer.

[Anonymous No.847513]

This is a schematics for dimmer im making to regulate speed on universal ac motor, so what value should i measure on output pins to see does it work ?

[Anonymous No.847523]

>>845004
the gearbox is a separate part

[Anonymous No.847529]

>>847513
RMS voltage

[Anonymous No.847537]

>>847313
those are toys, dude.

>>847303
get yourself a PLC and start learning its language.

[Anonymous No.847574]

What should I be looking for when buying a Soldering Iron?

[Anonymous No.847578]

>>847574
choose size and wattage depending on use

[Anonymous No.847582]

>>847578
Would a 60w one be good enough for a beginner that is only messing around with some small eletronics?

[Anonymous No.847585]

>>847582
yes
if it has adjustable temperature it is better

be careful of the temperature specification because you dont want to overheat

watt =/= temperature
watt is purely how fast it gets hot

[Anonymous No.847591]

>>847585
Okay, thank you.

[Anonymous No.847635]

>>847582
>>847585
You want a temperature regulated iron. Cheap adjustable irons only control the amount of power used to heat the tip, but they can't maintain a steady temperature.

[Anonymous No.847716]

http://youtube.com/watch?v=iHFm-kVTXW8

Why some eevblog videos make people so butthurt?

[Anonymous No.847724]

>>847716
>why are there processor fanbois
I have to admit that I can't stand that faggot. Which is a pity, as he seems to be knowledgeable and his topics are often interesting.

[Anonymous No.847730]

>>847716
>rants against assembly programmers
>hacker/maker culture didn't exist 5 years ago

Can't be arsed to actually dislike the video or leave a comment but I can see why people are angry.

He's spoken highly of certain applications of ASM in other videos, probably just dealt with an annoying "everything is better in assembly, I write assembly to take advantage of incomprehensibly complex machines better than the result of 40 years of compiler research, I think that my Real Programmer idols wouldn't use high level languages even if they were as good in the 60's as they are now" type before he made the video and got riled.

I will admit I did get upset when he dissed optimization and said "just buy a better chip", that attitude is killing this field

[Anonymous No.847743]

>>847716
i like to post references to outback steakhouse on his videos and talk about bloomin onions. he's a hardcore fedora tipping atheist and he's really jealous of America.

[Anonymous No.847789]

>>847093
Do you actually know that the only thing wrong with the PSU is the capacitor?

If you don't, and the damaged capacitor is one of the larger (i.e. more expensive) ones, I'd suggest just getting a new PSU.

Whatever damaged the capacitor may well have damaged other components. When capacitors fail, they often exhibit visible damage (e.g. burst casing). Semiconductors are more vulnerable, but they rarely show physical damage, they just stop working.

[Anonymous No.847807]

so i snagged some burned out boards from work, and was able to recover the following chips:
ne555p x 1
rc4558p x 4
uln2002a x 6

i also have an ft232h breakout board i can fumble around with.

i'm brand spankin new to this hobby and have very little theory mastered. regardless of that, is there anything fun i can make with this stuff?

[Anonymous No.847823]

>>847743
That's every Australian though

[Anonymous No.847825]

>>847823
oi seppo cunt say that to me face and not online we'll see what appens then cunt

[Anonymous No.847946]

>>847716
He's a right cunt that's why

Maybe not overtly but in a subtle sort of way, some things he says rub me the wrong way. Like the way he obviously has some brands he will never like and some he will never speak ill of

[Anonymous No.847967]

>>847807

You can do some fun stuff with the ne555 chip. It's a good thing to look into for introductory projects; you'll be blinking LEDs or whatever, or creating a monostable system that can be useful when paired with other systems.

The uln2002a is a bunch of darlingtons, not very exciting on its own.

The rc4558p will let you fuck around with op amps, also pretty fun to work with and a lot out there for basic projects to try out with them.

Granted, for any project you're going to need the resistors, capacitors, etc to make the chips function.

[Anonymous No.847997]

>>847303
Get a avr dragon or something similar, download atmel studio, buy some chips. There's a decent number of tutorials that teach you stuff, Patrick hood Daniel on YouTube has a good series. If you aren't familiar with the basics of programming, learn some C, youtube has a bunch of tutorials, thenewboston does great tutorials. I've been messing around for a few months and I've learned a lot doing what I said.

[Anonymous No.848011]

>>845099

[Anonymous No.848014]

>>847789
Just bought a Cap for an equivalent of $2.50 in my country's currency. Though I'm aware there isn't quality control over here when it comes to electronics but I'm willing to take the risk. Got myself a Rubycon 560uf 200V while the ones in the PSU are Teapo with the same values. I don't know quality capacitor brands.
The area around the blown cap seems smoked and it seems blew up from the top and from the bottom. The parts surrounding are a 2(or 3 Watt resistor, the main's cable and a semiconductor which I can't see it's part number (might be a SCR, TRIAC or something similar).

>>847133
Welp, I just realized we have 2 diferent lines (not sure if it's biphasic). The one that got pulled was neutral.

[Anonymous No.848029]

>>847997
Don't bother with an AVR Dragon, get the Atmel-ICE instead. The basic version costs the same, but it's more versatile and robust.

[Anonymous No.848185]

>>847256
That's exactly the chip I was using. It's quite obvious the leakage current is affecting the performance of the circuit. With a mechanical switch, the integrator has control of +-9 Volts. With the HTC4066 only about 50 mV.
Wouldn't a transistor still leak some current even when the base is biased to not allow Ic through?
>>847250
The integrator doesn't perform as it does with a mechanical switch. I'm assuming this is due to leakage current.

[Anonymous No.848201]

>>848185

i havent played with the 4066 in a very long time, but when i did, i found it had numerous issues, including the fact that one switch can interfere with another. the datasheet makes it sound very nice and simple, but it isnt, there are numerous trap-falls.

i would look for a small relay instead, preferably the kind you find in room heating controls, that latch, so you dont have to keep feeding them current.

[Anonymous No.848210]

>>848185
>the integrator has control of +-9 Volts
What is this supposed to mean?
In any case, 74HCT4066 can't handle +/-9V supply or signals, so apparently you overvolted it in some way.
Also, consider redesigning you shit so that it isn't overly sensitive to leakage currents. This is to say that design it so that ordinary components are good enough.

[Anonymous No.848224]

This is a really dumb question, but do all circuits need to be complete.

Does all the power going into my home need to be on a complete circut back to the power plant.

I know it's AC, but I still can't visualize how this works in my head

[Anonymous No.848231]

>>848224
Low(er) voltage power lines might have just one single phase wire for the live with the actual ground acting as the electrical ground.

https://en.wikipedia.org/wiki/Single-wire_earth_return

[Anonymous No.848234]

>>848224
3 phase power generators. Each phase is 120 degrees off from each other. Then through local power stations, we can turn it into DC and send it to your house.

Shit's a lot longer than this, but it's a gist.

[Anonymous No.848249]

>> Does all the power going into my home need to be on a complete circut back to the power plant.

of course. just as with a battery, any electrons coming towards you on 1 wire have to be sent back on another. the Single-wire_earth_return thing is dangerous and inefficient coz it's using dirt as the return wire.

[Anonymous No.848255]

I was testing an SCR for rise time using a potentiometer to trigger it and having 5V go through an led at the anode end. I used my o-scope to measure the time it took for the voltage to ramp up, and it came in at only 30 nanoseconds, but the datasheet specified a rise time of 50V/us.

Is there something wrong with the way I tested the SCR or am I missing something?

[Anonymous No.848256]

>>848249
You do realize that neutral just connects to the ground outside your house, right? Dirt may be a crappy conductor, but consider the size of that conductor.

[Anonymous No.848258]

presumably the 50V/us is a maximum, so your 5V in 30ns is well below that maximum. no problem here, boss.

[Anonymous No.848259]

> You do realize that neutral just connects to the ground outside your house, right? Dirt may be a crappy conductor, but consider the size of that conductor.

hehe, wrong. neutral is the center tap of the 12kV to 220V transformer outside your house. it also connects to ground, yes, but there is a low-impedance path to your house for certain in the form of a heavy un-insulated wire.

[Anonymous No.848260]

>>848249
>the Single-wire_earth_return thing is dangerous and inefficient coz it's using dirt as the return wire
Explain how it is dangerous and what would be your alternative to the earth ground

[Anonymous No.848262]

>>848255
Sounds like that parameter of yours is the maximum allowed dV/dt. You need to design your circuit so that the rate is not exceeded in order to prevent accidental triggering.
The actual turn-on time is expressed in (micro)seconds.

[Anonymous No.848263]

Wikipedia articles mentions a few points on safety of Single-wire earth return lines, but another i'm aware of is tickling from shocks since your two feet are at different potential. also, swimming in a lake can also be ticklish.

> Significant currents on the order of 8 amperes flow through the ground near the earth points. A good-quality earth connection is needed to prevent risk of electric shock due to earth potential rise near this point

> ... a broken SWER conductor can short to ground across a resistance similar to the circuit's normal load; in that particular case, a tree. This can cause large currents without a ground-fault indication.[4] This can present a danger in fire-prone areas where a conductor may snap and current may arc through trees or dry grass.

[Anonymous No.848268]

You guys know any chain supply stores? Im looking to get some mosfets and other assorted things for a project I just thought up and would rather not overnight them. Radio shack sucks, I know there's other stores in the area but don't even know what to Google to find them. Electronic components brings up best buy. I'm in detroit.

[Anonymous No.848271]

Future Electronics - 38800 Country Club Dr Farmington Hills, MI 48331

dunno how far that is from where you are. they're the only bricks and mortar store i'm still using. but, anyway, you can cross-reference their Yellow Pages listing to see what other stores are in same category.

[Anonymous No.848280]

>>848210
Tell me how else I can place a switch to turn off the integrator only.
chip doesn't receive 9 volts. The integrator is being fed an error signal, the output of the entire circuit is +-9 to a high voltage amplifier tocontrol a piezo.

[Anonymous No.848282]

>>848271
According to Google it's about 40 minutes, not too bad. Their websites down right now so I can't see what kind of inventory they have or if they're even open today.

I also found Micro Center, but their selection looks lame, some good stuff but they sell a lot of assorted 100 packs

[Anonymous No.848294]

>>848280
If that's the case, then you're feeding that +/-9V to one of the analog switch pins. You can't do that with HCT4066. Use another switch, for example HI-201, which can handle the required voltages.
Or use discrete mosfets or reed relays.

Better yet, design your circuit so that it tolerates some leakage. For example, don't require an integrator which can hold its state indefinitely. Design stuff so that certain droop rate is acceptable and optionally add a resistor to get a predictable droop rate (and offset).

[Anonymous No.848295]

I've never done anything with electronics. I've always wanted to. I'm not asking how easy it is, I have no problems with challenges. I would like to ask though, is this an expensive hobby? Can any careers come from this? And one big one, is it fun?

[Anonymous No.848312]

>>848295

It depends. You can get started with learning for under $100. There are also many, many projects out there that you can make that come in for that price range as well, and plenty of documentation and instructions for introductory projects. Heck, just take a look at instructables, there's a bunch of people helping new guys on there get up and running. They may not be great for theory instruction, but it's enough to get you started.

Career-wise, while you won't be filling any EE positions without a degree, it can help for positions that routinely work with them. As an example, I work as a mechanical engineer but routinely have to create working prototypes for some of the products we want to develop. This means working with arduino, PICs, and AVRs regularly. Being able to function with these development tools has been great for getting things up and running quickly, but one of the real great things is being able to talk with some amount of confidence and understanding to the EE guys when you want help from them on specific issues, as opposed to constantly asking them for basic instructions. They're a lot more helpful when the conversation can go both ways.

As for fun, that one's dependent on your personality. While electronics is interesting as a standalone hobby, it may not necessarily be fun. Fun, for me, is derived from identifying a goal, working toward it, and ultimately achieving it. Without a goal, there really isn't any fun. Generally this means for me finding some project to work towards; if you can't come up with something creative or something that is interesting to you, you may struggle in deriving enjoyment from electronics. Again, there's plenty of resources out there available to provide inspiration and guidance, but you're still responsible for getting the motivation and drive to see a project through to completion. Projects can range from simple learning exercises where you learn how to use an op-amp or a 555 timer to complex systems.

[Anonymous No.848315]

>>848312
Thank you very much. Very insightful. I enjoy computers as well and though it'd be a decent combo.

[Anonymous No.848319]

>>848312
Also, is the pastebin reliable?

[Anonymous No.848329]

>>848319

For the most part. The circuit design software should include KiCad, though. But that's probably not an issue; you likely won't require learning that for a while. If you want to learn circuit design software, I'd wait until you can at least sketch out basic circuits by hand first, then watch some video tutorials on it. Choosing your software package might also require some time and research to find what works for you, but like I said don't worry about that yet.

The rest of the pastebin seems for the most part accurate.

[Anonymous No.848331]

>>848260
3 phase bro. Having all the current return the the power company through earth is just a silly idea, earth has a range of resistances and on actual industrial installations if the earth isnt conductive enough they basically have to pour shit in it that is terrible for the environment. But it is still necessary to keep the return current path at the same potential as earth

[Anonymous No.848340]

>>848329
Well the pastebin was created so we wouldn't have to limit the OP to the word limit on 4chan. So please feel free add any information you feel it is missing.

[Anonymous No.848341]

Are they okay to solder in? These are lvel 3 parts. If not, should I just buy new parts?

[Anonymous No.848342]

>>848329
You have been wonderful, thank you.

[Anonymous No.848347]

>>848341
Moisture is only really a problem if you're doing reflow soldering (as long as there's no actual rust or whatever). Look up "popcorning."

[Anonymous No.848349]

>>848341
Fucking shit they changed their colors

[Anonymous No.848356]

>>848349
Shit they changed color but I forgot image
>>848347
Really? So should I just go ahead with these? They cost quit

[Anonymous No.848361]

>>848356
I give up, my phone is glitching.
>>848347
I searched tit up, but are the Methods described here
http://www.youtube.com/watch?v=3NN7UGWYmBY
Reflow soldering?

[Anonymous No.848373]

>>848356
>They cost quit
What?

>I searched tit up
What?

You suck at research. Reflow soldering is when the board is put in an oven which melts the applied solder paste.
https://en.wikipedia.org/wiki/Reflow_soldering

[Anonymous No.848377]

>>848361
No, that's not reflow, so it shouldn't be as moisture sensitive because it's not heating up the whole device

Also you can almost always bake the moisture out of the components if you have to. Check the back of the data sheet, or sometimes the manufacturer has a separate appnote on handling.

But for casual stuff you can usually just not worry about the whole moisture thing

[Anonymous No.848428]

>>848294
Omg I just told you the chip doesn't receive 9 volts. It gets 3.5 volts max.
I need an integrator. I need it to integrate the the error signal I'm feeding it so the feedback loop of my system is complete.

[Anonymous No.848477]

>>845516
Just make your own Arduino, part by part. Google or check Youtube, there are plenty of videos that teach you how to make your own Arduino using crystals, chips etc. You can make Arduinos for $3 a piece or so.

[Anonymous No.848583]

I'm looking for a way to amplify a voltage, I already have an inverter that outputs around 1 to 3kV peak to peak, I want to get 10-20kV. My plan was to use a Cockroft-Walton multiplier, I've used them many times and they work well enough, but I now I want something more compact. Can /ohm/ help me out?

[Anonymous No.848607]

>>847716
>support this channel

Is this a him thing? I can't see another channel I follow that has this.

[Anonymous No.848612]

I'm looking for a way to amplify a voltage, I already have an inverter that outputs around 1 to 3kV peak to peak, I want to get 10-20kV. My plan was to use a Cockroft-Walton multiplier, I've used them many times and they work well enough, but I now I want something more compact, also, all my diodes are rated 1kV, so I would have to order beefier ones. Can /ohm/ help me out?

I'm also looking for a module board for the L298N stepper driver, it is a popular driver and I was hoping to find an Eagle board or similar to print the circuit and use it. Any help is appreciated.

[Anonymous No.848629]

>>848612
Forget about the board, I found some.

[Anonymous No.848674]

>>848428
This is the first time you said how much voltage it is actually getting. Is it 0 to 3.5V or +/-3.5V? If the latter, how did you power the switch chip?

>I need an integrator.
And I'm saying there's no such thing as perfect analog integrator. You need to take it into account, one way or another.
One of the simplest ways to reduce the droop rate would be to use a bigger capacitor. How big is your current capacitor?

[Anonymous No.848919]

Favorite youtubers?
Who is the colin furze of electronics?

[Anonymous No.848931]

how to make a nintendo ds lite charger?

[Anonymous No.849035]

>>848931
Buy one for $5

[Anonymous No.849050]

>>848612
If you want really high-voltage, you can replace the diodes with active rectification using gas discharge tubes (e.g. xenon strobe tubes) as switches.

[Anonymous No.849092]

another stupid n00b question,

when i see the notation +/- 3.5v, is -3.5v a draw of 3.5v or is it simply positive ground?

[Anonymous No.849153]

>>849050
That sounds too complicated to make. I guess I don't have many options, I've seen stun gun circuits but I don't know how to use triacs. I don't know a better or simpler way to increase voltage than the ol' multiplier.

[Anonymous No.849157]

From:
>>849101
Discussion on trying to build an inverter output stage for a welder.

I couldn't find one where they paralleled IGBTs but there is some discussion here: http://4hv.org/e107_plugins/forum/forum_viewtopic.php?112858 and
paralleling MOSFETs if you must seems to be a better idea, plenty of people have done that

[Anonymous No.849278]

I have a question. This is my EMP stick, made with a flash circuit from an old disposable camera, and some old electrical wire from the house. I know I might need a better coil (maybe magnet wire) and simply form the coil better, but other than that and a bigger battery/capacitor, what could I do to make it work better? I have tested it, and it works on egg timers and such, but nothing more complicated.

[Anonymous No.849294]

>>849050
>>849153
I risked my oscilloscope and measured the output of the inverter using a voltage divider, according to the calculations the output is a nice sine wave with 500V peak, so I can rectify it and use 1kV high frequency diodes like BA159.

>>849278
Emp guns are quite shitty, magnetic energy is easily lost though the air as the distance increases, try adding a bigger cap, you can find them in power supplies, just make sure the voltage rating is around 400V to avoid damaging it, the energy stored in a capacitor is 1/2 * Capacity * Voltage^2 capacitors in cameras don't have more than 100uF.

I wonder if making all that energy pass through a MOSFET atrached to a high frequency oscillator so that all the energy is sent in pulses rather that a continuous discharge would increase the damaging power.

[Anonymous No.849360]

Don't know if it's related. I love modding electronics but most of the things I do are done with tutorials as I don't know almost anything about it but I want it to be my lifetime job. In September I'll start university again (left previous one for reasons) and I'm undecided: should I start with electrical engineering, get degree and then get a master degree in electronic engineering or should I go directly to electronic engineering?

[Anonymous No.849365]

>>848919
Dave from the EEVBlog

[Anonymous No.849368]

>>848931
Replace charger's port on the ds with a USB mini port. Og charger port is actually a modified USB mini port with no data pins (so make sure to bend those pins before soldering the other two on pcb), that's why you can stick a USB mini cable in a og port and get the right charge in the same time

[Anonymous No.849392]

>>849278
>what could I do to make it work better
Here's something to consider:
1. Youtube etc. is full of videos of these emp guns
2. Just like yours, they all suck.
3. Just like you, half of the kids building these want to increase the range.
4. Results: see point 2.

[Anonymous No.849406]

Question: I recently a 3-input/2-output passive audio matrix/switcher. It works great, except when I plug the computer in. Whenever my PC's output is connected to the switcher, I get a high-pitched hum/whine, which I assume is a ground loop. But the thing is, it's ONLY when the computer's plugged in. I got tired of hearing it, so I took it out temporarily, and again it works perfectly fine. Right now, my TV's headphone output is connected to the switcher's 3.5mm input (which was going to be the PC in). I'm wondering why this is.

If it matters, 1 input and both outputs are 3.5mm jacks, and the remaining two inputs are RCA.

Sorry if this doesn't 100% make sense, I'm starting to get a bit tired, it's 2am and I've been up most of the day.

Any help would be appreciated, though.

[Anonymous No.849495]

>>848201
I missed your answer.
I'll try that

[Anonymous No.849496]

Hello,
I have a 5.5V 120mA solar panel, can I hook it directly to a USB to charge my phone? Or would it hurt the phone or the battery?
I have a spare lm7805 but the dropout is 2V (the input would be 5.5 and output 5V), can I use it to make sure the output will be 5V? If the dropout is under 2V what would happen?
Thanks in advance

[Anonymous No.849502]

>>848674
Not negative. The HTC4066 gets positive voltage from a photodetector for the logic input. Gets powered by supply at 4.5 V.

[Anonymous No.849630]

>>849495
>>848201
It worked perfectly thanks

[Anonymous No.849733]

I need to reroute a bunch of traces so that I can replace with In-8-2 nixie tube instead of IN-14. However the problem is that the pinout is really incompatible so ill have to severly modify the original board. What things must i avoid when rerouting traces? The only on the board are 3 HV5622, 8 IN-8-2 resistors, and 3 capacitors

[Anonymous No.849764]

>>849733

Sure is divergence meter in here

I'm guessing at least

[Anonymous No.849812]

>>849733
Avoid vias like they're plutonium

[Anonymous No.849815]

How do I find out how much current I need going into the base of a transistor so that it will switch a relay? This circuit works with a 2n2222, but not with a BC548. How do I find out the value of R1?

[Anonymous No.849819]

>>849764
Yup.
>>849812
Avoid making vias or connecting multiple traces to them? Because some of my connections are possible because of vias

[Anonymous No.849825]

Posting here because I think maybe you could actually help me.

>>849312
>>849794

[Anonymous No.849839]

>>849815
uhhhh the hFE parameter is gain = Ic/Ib so take your current at the collector and multiply it by the gain of the transistor and it gives you the current required at the base.

[Anonymous No.849844]

>>849819

Just vias in general, they're a bitch to make

>>849839
And using that value I'll be able to determine the value of the resistor that goes to the base? How about the pull down resistors I've seen on some schematics? They're just there to reduce the voltage that goes into the base pin?

[Anonymous No.849848]

>>849844
Would this be a problem if I get my uni to manufacture it for me?

[Anonymous No.849851]

>>849848

Not at all, but I've seen people that charge more based on the number of vias you have on the board.

[Anonymous No.849855]

>>849851
Well that sucks. I've added at least 6 vias per tube. Guess I'll just modify the code instead.

[Anonymous No.849856]

>>849848
depends how good your uni is, the board needs to be plated and stuff its a pain in the asshole.
using a double sided board when you don't NEED to is a good way to make enemies.
you can usually replace vias with wire links if you just need to get from a to b.

oh man the base emitter resistor is probably some leakage current stuff related thing to make sure its off when its supposed to be. i don't know i'm not really an analog guy.

[Anonymous No.849873]

>>849294
Thank you for the idea. I'm not really trying to make a weapon, it's more to test the theory. I am more interested in trying to see if I can use the pulse generator to transport current wirelessly. The egg timer was just to see if it does have a voltage surge sent to the external circuit. Like you said, it would have to be an alternating current, but trying to aim the pulse and have it retain enough charge to be effective seem a bit troublesome. The circuit I used is just extra stuff I don't need. The capacitor has an output of 225 volts, but without it in front of me I can't remember the capacitance.
>I have no formal training in electronics, and I've taken physics 101 and 102, but I have little to no knowledge in electronics other than assembly.

[Anonymous No.849904]

managed to save a deathadder I thought was done for. I found it in a drawer and noticed the wire was frayed at some spot and the wire inside was broken. I thought it died because I spilled something on it not because of the wire. I disassembled it and unplugged the cord, then plugged in another one from another unused mouse after I rearranged the new cord's wires to match the deathadder.

plugged it in and it works like fucking new.

[Anonymous No.849935]

I fucked up and think my ICs are dead. Will replacing them work?

[Anonymous No.850065]

> I fucked up and think my ICs are dead. Will replacing them work?

that's pretty much all there is to electronics repair: you pull out the bad bits and replace with new bits. the only tricky part is knowing which are the bad bits. and the other only tricky part is having the skills to do it without causing further damage.

[Anonymous No.850089]

>>849825

nah, dude, we dont care about your fruity round transformer. anything but square is heresy.

[Anonymous No.850096]

I plan to make a solid state Tesla coil and I wanted to clear some doubts before I screw it up. Here's what I plan to do:
-For the primary power input, a transformer, some capacitors and paralleled MOSFETs, making some calculations and hoping they can discharge the capacitor without blowing up.
-For the primary I have no idea how to place the coil, I don't know if to go for the simple loop of cable arount the base or the fancy cone shaped primary nor the differences between them.
-For the secondary I'll go for the classic PVC pipe, I guess I'll eyeball the size and turns, I have no idea how to estimate this either.
-For the toroid capacitor I plan to use metallic ventillation tube.

After this I'll adjust the frequency and all that stuff to optimize the performance.
Any tips on how to get streamers? I have ~0.3-0.4 mm copper wire, I'm afraid is too thin and causes the voltage to be high enough to lose it very easily.

[Anonymous No.850097]

>>849406
Anyone?

[Anonymous No.850110]

>>850097

it's a mysterious problem with no obvious solution, so try some shit until it works right.
- put a load across the PC output to see if it stabilizes - try diff values
- put a cap across it to short out the high-frequency stuff - try diff values
- plug in a real audio card if you're using the embedded shit.
- give up on that and use a USB sound card, which provides a layer of isolation from the dirty noisy PC environment
- kill yourself if none of that works

[Anonymous No.850115]

>>849496
I don't have too much experience w/ solar panels, but I'd advise having a reliable and constant current when working with anything expensive/not replaceable
Some caps and a resistor ladder could do the trick, but you might fuck up the current and not be able to charge your phone

[Anonymous No.850131]

I'm planning on buying the tools for building electronics.
I've been looking on other websites and i'm still not convinced on buying two osciloscopes 'just because sines eggsdee', i want to hear it, what are the absolute basics i have to get.

[Anonymous No.850132]

>>850065
>the other only tricky part is having the skills to do it without causing further damage.
This is what I was really worried about
What should I keep in consideration?

[Anonymous No.850160]

>>850132
> What should I keep in consideration?

proper tools and practice. youtube has videos, of course, about everything, so watch and try it out on old equipment you find on the curb.

[Anonymous No.850167]

>>850132

oh, i suppose i could give one hint: if you know the chips are dead, or they're cheap to replace, then you can simplify the job of removing them enormously by cutting off the pins and then removing them 1 by 1 instead of desoldering the whole chip.

[Anonymous No.850183]

>>850132
The way I usually desoldered chips is I lay some desoldering braid (literally just a braid of copper wire) across all the leads and then heat up the braid. The solder will take to the copper and it sure as hell beats desoldering each pin one at a time.

You have to be careful doing this to retrieve a chip though since it can easily damage heat sensitive chips. But if the thing is shot anyway then it doesn't really matter.

[Anonymous No.850295]

>>850131
30w Soldering iron
Black and white laser printer
Solder wire
Ferric chloride
Clothes iron
Multimeter

That's about it

[Anonymous No.850301]

Concerning broken ICs, is there any way to know what happens if they're dead? I'm trying to figure out why all my nixie clock digits are just lighting up and which IC is dead. Only thing iI saw was my fuse glowing.

[Anonymous No.850312]

>>850295
You don't even need to start with printed circuits, Manhattan assembling works pretty much the same even at UHFs, is faster and cheaper: you just need cyanoacrilate and pieces of boards that you can just cut off any board

[Anonymous No.850315]

>>850089
I used to think so too, but they're actually pretty neat.
muh efficiency

[Anonymous No.850319]

>>850096
I've done some research and I'll probably use this circuit but with beefier mosfets and caps. Am I missing something? Is there a better circuit in your opinion? My goal is to achieve around 1kW.
Maybe replacing those .68uf by 1uf?

[Anonymous No.850321]

>>850319
Forgot picturr

[Anonymous No.850372]

>>850319
>no streamers

Try adjusting the coupling by raising/lowering the primary, increasing or decreasing the number of primary turns, and increasing/decreasing the diameter of the primary. Removal of the toroid might also help.

If you're new to SSTC building I suggest you build a "slayer exciter" circuit, which is simpler.

[Anonymous No.850467]

Frustrated with designing circuits.

tips?

[Anonymous No.850489]

>>850467
Drink tea, lie on a bed and think about anything else

[Anonymous No.850497]

>>850489
Fucking this

[Anonymous No.850500]

>>850301
If you mean testing them, you could just probe the outputs to see if they're behaving correctly.

[Anonymous No.850527]

Do you guys have any ideas for where I could source a cheap 24v battery?

I checked at goodwill hoping there'd be a 24v drill there and I could just rip the battery off that but no dice.

[Anonymous No.850531]

>>850527
Is there a Batteries+Bulbs near you?

[Anonymous No.850533]

>>850531
I've never heard of it, I'm in Toronto canada

[Anonymous No.850579]

>>850531
Batteries Plus is the bomb diggety
Also, fuck you. I'm not calling it batteries plus bulbs. Batteries Plus is way better.

[Anonymous No.850586]

>>848234
what the fuck am i reading

[Anonymous No.850587]

>>850500
This means desoldering the component? I guess I'll just solder in a new instead since I've already ordered replacements. It's sad because these things are $10 a piece...

[Anonymous No.850594]

How do you get into making electronics as a hobby? I designed and built a thing, because I needed a thing, but now what? I don't really have a need for anything else. What do you guys even make?

[Anonymous No.850596]

>>850586
fucking google 3 phase

[Anonymous No.850602]

>>845086
put the leads through, bend the leads at a har angle, clip the excess, solder,

[Anonymous No.850603]

>>850594
>Maybe not overtly but in a subtle sort of way, some things he says rub me the wrong way. Like the way he obviously has some brands he will never like and some he will never speak ill of

i wanted some soft LEDs underneath my kitchen cabinets so when i get up in the middle of the night to raid the fridge i break a beam and the counters are most dimly lit and if i wave my hand under the counter once it goes to medium. twice to bright. third to off. I can find my way back in the dark.

with sammich.

[Anonymous No.850610]

>>850533
http://toronto.craigslist.ca/tor/bop/5126073179.html

30 seconds on craigslist, try kijiji also

[Anonymous No.850628]

What would be the best way for me to acquire a bunch of electrical components for as cheap as possible? Are there any really cheap kits with tons of components? Should I just take apart old electronics? I'm talking power supplies, capacitors, magnet wire, etc. I already have meters and other equipment.

[Anonymous No.850652]

>>850372
Thanks for the tips. Some hours in google and youtube made me stumble upon the holy grail of homemade Tesla coil information.
http://www.loneoceans.com/labs/sstc2/
There are many other designs and a lot of information, this will do the job.

[Anonymous No.850662]

>>850628

[Anonymous No.850677]

Complete noob here:

I've got an arduino uno + easydriver that I want to hook up to dragonframe so I can control a stepper motor camera slider.

This is the motor I'm using

http://www.robotgear.com.au/Product.aspx/Details/410-Stepper-Motor-Bipolar-200-Steps-Rev-12V-0-33A-2300g-cm-torque

How do I go about powering the easydriver?

Can I just get a ~12v ~1-2A power adapter, strip the wires and solder them to the board?

Is there a way I can somehow power it using something I can remove that isn't soldered?

Thanks

[Anonymous No.850739]

>>850662
Are EEPROMs and random chips worth salvaging?

[Anonymous No.850742]

>>850739
no longer manufactured, rare chips, hard to find

[Anonymous No.850745]

>>850662
heat the solder side of the board with a propane torch. parts fall off into 5 gallon bucket.

[Anonymous No.850747]

All this talk about desoldering en masse makes me want to make some sort of oven designed specifically for removing all components really quickly.
Might be a fun project.

[Anonymous No.850908]

How's this book for someone who knows nothing about electronics?

https://docs.google.com/file/d/0B5jcnBPSPWQyaTU1OW5NbVJQNW8/edit

[Anonymous No.850931]

>>850587
> This means desoldering the component?

nope. it means using a scope or voltmeter or logic probe to look at the voltages and signals present to see if they match what they're supposed to look like. this implies you either have someone with a working unit document what the signals should be like, or a deep understanding of the electronics involved.

[Anonymous No.850934]

>>850908

it's a classic, but it's more geared towards people who wanna build cool stuff (cool as in ''a circuit that makes a cricket sound'', not as in ''sending a camera into outer space'') rather than those who want a deep understanding of all the math and principles that underlies all the design choices.

[Anonymous No.850949]

>>850934
Should I read it though? I want to eventually be able to build stuff like simple robots using an arduino or maybe just a microcontroller that can be programmed in C.
I mean, is it good as an introduction for someone completely new to it?

[Anonymous No.851028]

>>850949
> Should I read it though?

it's a silly question. read the first 5 pages and if you like it, and it feels useful, keep reading. it's as good a place as any for an intro to all kinds of digital and analog circuit and concepts. it's all low-level stuff tho, no CPUs, you need a second source for that.

[Anonymous No.851041]

>>851028
I know it's entry level.
I already know programming and know what logic gates are (but I can't build them).
I want something that teaches me voltage, current, where to connect the wires (where to connect to the + and -) and what diodes, capacitors and other components are.
I've read a few pages and it seems to be about that, I'll start reading it tomorrow since I'm tired today.

[Anonymous No.851071]

I fucked up and managed to remove the SMD pads for an IC. Though I did manage to secure the circuit using a wire, I can't help but feel that that little lead will just come out of the IC. What should I do to secure itll never come off? Super glue it?

[Anonymous No.851192]

>>850745
Genius

[Anonymous No.851238]

>>851192

yeah, it's a genius idea until you try it. then the stench, the smoke, and the frustration of parts that dont wanna come out will keep you from trying it ever again. unless you're Bangladeshi and desperate.

[Anonymous No.851239]

>>851071
> Super glue it?

ideally, you always want a way to reverse a procedure later. unless the thing is gonna be handled or subjected to lots of vibration, you should do nothing. otherwise, a drop of hot glue will secure it.

[Anonymous No.851259]

Hakko FX888D vs Weller WES51. Which and why? What exactly is the difference between both?

[Anonymous No.851285]

>>851259
I really like my Hakko. Being able to control the temperature the tip is at is an underrated feature. It means I can set the temp and not worry (as much) about burning parts. Looking at the Weller, it seems it's got temperature control too, but I've never used an analog temperature control.

[Anonymous No.851287]

>>851285
It's the same shit, anon. The digital can be more precise (=/=accurate) but 5*C won't make any difference really.

I'm more worried about 'real temperature control' (Sensor at the pen that changes the current supplied depending on the load to keep the temperature constant) on the Hakko, as I've read it doesn't have such feature. Unsure though, and don't know about the Weller. Hope someone clears it up.

[Anonymous No.851292]

>>851287
No, the Hakko just turns the element on and off. IIRC if you have it in the mode that shows you the temperature as it warms up, and it gets out over 10c, it'll switch over. I've never seen switch over while I've been soldering.
I did see it switch over when I was bored and filled an Altoids tin with waste solder.

[Anonymous No.851297]

>>851292
Thanks m8. Any idea about the Weller?

Also, what are the key differences between both if you will.

[Anonymous No.851396]

is there a shortcut to sourcing components? i am getting into modifying tube amplifiers and it is a hassle to go through mouser and find every value of capacitor that I will be using. i bought a 1/2 watt resistor set but really it is the capacitors that are being a nuisance.

[Anonymous No.851431]

>>851396
you can buy sets of capacitors, too. Also, ebay and/or cheap chinese dealers are fine for non-critical components like small value caps and resistors. I wouldn't trust power capacitors or large transistors, though.

[Anonymous No.851698]

Hi guys, I'm still working on my clock & led project. Here is the circuit, I didn't found the value of the last resistor but that's not the problem yet. Do you think that the clock work for a long time if the le circuit is open ? Do you know a better way to make that kind of circuit ? Or a good way to calculate how long it will work with and without the leds on ?

[Anonymous No.851739]

>>851698

insufficient data.

[Anonymous No.851874]

>>851698
>>851739
All that I have gathered: 16 led of 3.4 V and 0,02 A. I used a simple formula to get the type of resistor that I need. More than the lights I want a quartz clock to work with the two 9V battery. The switch is here to turn off the light when I don't need them, but I wonder if my clock (usually powered with 1.5V) will last long
with this circuit (and the adequat resistor) or if you have a better idea.
If you can't help me with this datas I gess that it means that I have to try... Anyway thank you guys.

[Anonymous No.851917]

>>851874

let's assume the clock takes 1mA (wild guess). a typical alkaline 1.5V AA cell has 2222 mAh of capacity so it would last 2222 hours. a 9V battery has about 555 mAh, so it would last 555 hours. having 2 in series doesnt change that. since it's powered from 18V, the clock-resistor circuit will take 18mW, whereas the 1.5V cell would only need to put out 150uW. so there's wasted power, if that matters. if it does, you could power the clock from just one of the batteries, getting the positive wire from the junction between the 2 series batteries. alternately, you could use a separate 1.5V cell for the clock.