/diy/ - Do It Yourself

So I'm (>>1926877, >>1926885), and now I've got this light bulb housing that I can relatively safely reuse. My intention is to make an LED bulb that can be turned on and off with a remote control. Dimming would be neat, but would complicate things a lot. I've got an IR remote lying about and I think I can salvage an IR receiver from another circuit of mine too.
That previous circuit first consisted of a low-pass filter, then a schmitt trigger to turn the erratic information-carrying signals from the remote into single pulses. I then used a dual JK-flip-flop IC configured as a T-flip-flop in order to convert each pulse into a single trigger. IIRC I could use a 556 timer IC or for both of these purposes and get away with one less IC, but whatever low voltage supply I cram in there needs to have as low a quiescent current as possible for obvious reasons, and 555s are shit for that. Last time I used a resistive dropper plus a zener for this, but this time I think I can use a capacitive dropper without issue, so long as have the diodes in the right positions, pic related. Not using a full-bridge in order to keep my 0V rail at 0V. Still no idea about the LEDs themselves though, like whether I'll be using a mains voltage string (probably not). Won't be high-power though, because I'm a basement-dweller who prefers sub-3W / sub-200lm LEDs.

Any thoughts on how to improve this concept?

>>1927461
Oh and that small arrow points to where an extra diode might be a good idea, due to the zener sinking a bit of current out of the capacitor. Actually I can probably just replace that first parallel diode with a zener instead, though I might have the same issue.
There's an option to add a 5V linear regulator after the zener, else use a more advanced type of shunt regulator instead of the zener. Like a TL431 and a pass transistor. I'm on 240V mains btw.

Also current limiting resistors on a capacitive dropper are for chumps.

I started a new project to build a usb hub with some other chips to interface with various instruments (SCPI, etc) and I got excited and kept adding stuff. Now that I'm laying it all out, I totally have lost interest in how massive the project got. Anyone have good tips to stay focussed and stop feature bloat?

Damn son, this shit is fucking small. Joining new wires to it was hell and I didn't have anything quite small enough. Amazingly it works

>>1927500
Constraints give your projects direction. Be it a size constraint, cost constraint, or a constraint to just use parts you've got lying about. For a size constraint, try using an existing case to cram it inside. Or you could aim to make it more flexible, by having a barebones main-board with optional addons on daughter-boards that you can make for it in the future.

For me, most of my constraints are on what parts I have lying about, since I order parts from overseas and the shipping times are abysmal. The result being, I order only the most versatile components and stick to simpler projects. Wish I had a local Digikey or Farnell or Arrow warehouse to order from.

I'm getting into the motor control and three phase power electronics rabbit hole. please send help

>>1927540
Just buy a dozen half-bridge drivers and some general-purpose MOSFETs to use them with, you'll be fine. Get a heat-sink too.

>>1927542
How do you use H-Bridges for three-phase motors?
Make inverters with them for a VFD?

>>1927542
no man, the vector control rabbit hole. I just hate how little text books exist on power electronics. As soon as you step out of the basics it's app notes and thesis..

>>1927543
Yes. The actual topology of the switching ends up being more of the same but how you control it is very important.

>>1927500
If you've got a breadboard to temporarily lay it out on then iterate through versions of it so that at the end of each version you have a working circuit.

I was given this fat fucker the other day. Supposedly its handheld but i fell like a fucking dwarf. Maybe hands were bigger in the 90s but i cant recall that being the case. It even has some signal generator feature. Must have cost a fortune when new.

>>1927584
>Supposedly its handheld
The term "handheld" electronics gets a lot more tenuous the further back in time you go. It was a different time.

>>1927584
who gives you that? mind introducing us??

>>1927595
>Handheld

>>1927312
high af

>>1927648
Hehe. Friend of the family. He's an engineer but retired and now he just focuses on his farm, so he gave me basically all his stuff. Pic related amongst other stuff also. A bunch of plc and their programmers too which i have no idea how they work but all the manualls were included so i have things to keep myself occupied with for a while i guess. Ten boxes of misc components also. I have now idea where to start sorting it though, but im really greatfull.

>>1927584
Here it is in action

>>1927699

90% of the fun of using a scope is the twiddly knobs. that thing is an abomination.

>>1927695
>Free analogue o-scope in good condition

>>1927703
100% of the fun of using a scope also comes from having one.

EE lab in 3rd world college

>>1927456
so i bought 100% pure latex cock rings from aliexpress and it had the RoHS logo on its package, haha

>>1927703
peak "maker" cringe right here

>i dont get an osciloscope to measure or test anything, it's just for the vintage knobs lmao :) :)

neck yourself

reminder that it is LITERALLY IMPOSSIBLE to interface with a computer without a Raspberry Pi or Arduino, it has never been done and computers are 100$ standalone objects that have to be connected to via IoT or BlueTooth

>>1927545
Thats because electronics is a science and people who say otherwise are brainlets that feel inferior because they never finished school

>>1927712
UFSC?

>>1927584
Handheld before meant it had a handle or is able to be held by one hand by weight

>>1927724
wouldnt then MORE textbooks exist?

obvs power electronics would be just one class (source: t. me, did EE, it was one semester's class) and once you're done it now you get into design using those basic principles, but with how much of a racket scientific textbooks are youd think the world would be lousy with power supply related textbooks

>>1927724
I think it is because :
>at large power ratings power electronics is exclusively for companies (non-hobby) and gets really complicated
>it is still changing (at those power ratings)
The only reason I have IGBTs with me is because my university threw a lot of old projects away and I scavenged some, in other conditions they§d be 20$ each

>>1927712
My lab looks like that in my first world university. What more do you need really to get a feeling of how the device works

>>1927728
Once you get i to higer level academia textbooks stop existing and your textbooks are the papers and app notes from which you hand dpick info and write it down into your own personal notes and then study that

>>1927713
Nice what size cockanon

>>1927706
I dont know why people fawn over analog scopes...i got a few digital ones from 1ghz to 200mhz and got an analogue one as a gift , and i never even used it yet because there is no purpose....i had to plan a project im doing specifically to be able to use an analog scope for its no signal injection property (which is also not that nescessary because i have differential probes that also do that but oh well)


The screen is pretty i guess tho

>>1927500
>Decide to make a project that does one thing
>Dont make it do other things

>>1927731
but that's wrong, until you get to the graduate level

and wiring up a washing machine motor is not graduate level

>>1927736
>there is no purpose
thats just you, because you are a retarded wypipo who just lights up LEDs to make yourself feel like a "maker"

>>1927461
there is a schmit trigger with a capacitor design used in old war planes that basically needs no power supply and feeds off of the signals coming in idk what its called ..you could use one of that with the ir diode and use that to flip a JK bistable like switch to power on or power off the LED circuit over a MOSFET

>>1927736
>itt rich americans with disposable income and cheap good instruments available
>>1927741
>and wiring up a washing machine motor is not graduate level
I was talking about vector control, not wiring. and the other anon was right, books simply stop existing after a certain point in Power shit

>>1927747
>books simply stop existing after a certain point in Power shit
yeah because the basic principles are all covered and now you're getting into specific applications

you don't want a textbook, you want an instruction manual like out of a LEGO set. fuck you

>>1927741
>and wiring up a washing machine motor is not graduate level
wiring up a washing machine hardly requires a textbook if you know which connection points are what

also all my textbooks that i used or saw had at least one type of driving circuit for each type of electrical motor and can be found anywhere since the end of time ...new driving methods are mostly proprietary and are used in commercial or industrial applications and will not be in textbooks because they are not used as basic solutions to show proof of concept and will almost always only be shown in app notes because you are trying to apply them to a device not study TI-s motor driver IC

>thats just you, because you are a retarded wypipo who just lights up LEDs to make yourself feel like a "maker"
boomers and hipsters always get mad when you touch their tubes or analog scopes ....i make industrial controllers for a living but you can think what you want ...i have yet to find a use case where an analog scope with 200mhz is superior to a 1Ghz digital one and i would absolutely love it if you can give me ideas for what that purpose would be so i can test it out and have a reason to use a machine thats gathering dust on my bench

>>1927750
You can find detailed information on lots of advanced topics on other areas, e.g motor control, dynamics and construction.
Because power electronics is still changing quickly I don't think anyone bothers. and systems become increasingly complex both in device and uh system level, I don't think there are good ways to aproach that topic rn

>>1927741
Why is the brown subhuman being uppity again?

>>1927757
>new driving methods are mostly proprietary and are used in commercial or industrial applications and will not be in textbooks because they are not used as basic solutions to show proof of concept and will almost always only be shown in app notes because you are trying to apply them to a device not study TI-s motor driver IC
this is basically what i was getting at angrily in >>1927750 and >>1927741 -- that the basics aren't that complex and will carry you very far, on top of it just not being a textbook's job to give you step-by-step instructions on specific applications, but just to lay out the core concepts and how they interact

>.i have yet to find a use case where an analog scope with 200mhz is superior to a 1Ghz digital one
usually stuff between the 1khz and 150mhz range

>>1927747
>itt rich americans with disposable income and cheap good instruments available
im neither american nor do i have disposable income ...i got a very good deal because i contacted a keysight seller that was advertised on EEVBlog i recommend you do that ...also i didnt buy it for shits and giggles i bought it because i was hired to do a job and i could pay it off with it ...if you dont earn enough money by working to get better gear either stop undercutting yourself or you are a hobby electronics user (which is fine and you should not spend a lot on gear if thats the case anyways since its not good economical practice )

>>1927758
And I remember one of Pease's (or was it WIdlar, I don't remember) texts saying how Power electronics controllers were notoriously dificult to make and explain. (Not talking about the converter itself but the controller IC).

>>1927762
>usually stuff between the 1khz and 150mhz range
again im curious why an analogue scope would be superior for that agains a good DSO (it has both persistance and live signal tracing at full speed )

>>1927763
>>1927760
>>1927757
>>1927750
Salty people

>>1927736
>the screen is pretty
Bang on the money. Also, I'd imagine it's easier to obtain an analogue rather than a digital in certain countries / areas.

>>1927766
the analog scope can be had for 5$ at an estate sale, that's why

>>1927764
high power stuff is either very expensive or there are no semiconductor technologies that are able to withstand it...today its much better beause IGBT and SiC semiconductors allowed higer powers to be used effectively but they are still relatively expensive ...once you get to that point heat generation becomes a great issue and with that regulator accuracy goes along with it , also low power stuff you can turn on and tweak on the fly where high power stuff blows up and requires you to be able to make a good regulator that can withstand high energy fluctuations effectively
also 1% at KW is huge 1% at mW is negligible energy so that also is considered very important

and thats all i you consider mostly analog controlers with some DSP ...when you go full DSP things get finnicky because new driver topologies are used that are not as tried and tested as the ones before and you have to do it all over again with the same problems you faced before

>>1927767
go troll somewhere else...we are not your parents to give you attention or are we interested in the circumstances of your failures

>>1927774
this is still not a problem you'd see in textbooks since it relates to real-world materials and their properties

same reason computer graphics textbooks don't go on about specific video cards, it doesn't matter to the core subject, it stays the same regardless

>>1927772
but i have the others already lol ...i said got it gifted after i bought the ones i use

but yes i absolutely agree if you need a scope for cheap and fast get an analogue one it will do most of what you need...im just saying that people that insist its the end all and be all of oscilloscope technology are retarded and should be shot


i like when they used amber screens more than green tho

>>1927780
im not op that asked why its not in textbooks ..im just adding to the post about why its difficult

im this one >>1927731

Changing the subject; What are you working on /ohm/?

>>1927786
serial ports

>>1927786
im troubleshootin an AOIP PJ 6301 calibration standard

i had a thermocouple connected to it for some time to get long term readings ..and one day something messed up and it reads wrong on the input side ...outputs are all spot on and working well

there was bad weather here for a while i wonder if there could have been an EM spike from a thunderstrike that induced a current/voltage in the thermocouple (its about 1.5m long) that give it a strong enough impulse to mess somethign up

>>1927723
I often hear people saying "you need atleast a raspberry pi or (one of those wifi thingamajigs) to atleast get started" and I find it retarded. Ngl, I use arduinos to pass stuff from other projects to the PC because it's way simpler than
>getting a usb-serial port adapter to use only 1 (one) serial pin
>godforbid mess with bit banging and USB

>>1927806
It is literally impossible to pass serial data into a computer except by Arduino or WiFi/BlueTooth/5G

>>1927774
dude I need to know how the Itaipu HVDC converter was designed. My brain can't wrap around the size of that shit

>>1927808
Just 3d print one bro.

>>1927723
>>1927807
>>1927810
Remember to ignore bait posts and keep this board at least partially non retarded

>>1927814
Oh? You think you can connect things to a PC without an Arduino or Raspberry Pi? Name even one other method.

>>1927818
stm32

>>1927819
>stm32
Wrong. Enjoy blowing up your computer because you didn't put a voltage buffer in. Lol.

>>1927794
I got to poking around ...one of the three volatge rails (+15V -15V and +5V) is lower than it should ..the +15 is showing 4.3V

>>1927821
just because you're not capable of doing it doesn't mean it can't be done

>>1927823
It is literally impossible. You are a moron. There is a reason there are not textbooks on power voltage applications... It's too dangerous for retards like you to understand...

>>1927827
>just because you're not capable of doing it doesn't mean it can't be done

I can't think of what the opposite of stranded wire is. Obviously not single core. Solid?

>>1927834
solid

>>1927543
Three half-bridge drivers, each feeding two N-ch MOSFETs.

>>1927545
>vector control
Isn't that just a simple matrix multiplication or something?
Also the plural is "theses" but that's neither here nor there.

>>1927560
Not him, but I doubt it will be possible to breadboard any kind of modern circuit made of SMDs on a breadboard, to say nothing of the speed issues. He'd have better luck doing some sort of semi-planned manhattan board.

>>1927856
>manhattan board
I've never actually heard of that. I've saw the "deadbug style" (just learned the name) before but not the former. Looks rather impressive but also rather fiddly. Maybe it's just the level that I'm at but breadboards seem ubiquitous when it comes to prototyping thanks to the ease of online shopping; Is it a generational thing?

>>1927794
>>1927822
something is fucky with one of the trafos (the one with black writing )

one of the outputs is dead but it has 4 outputs (8 pins) for 3 voltage rails so it kinda looks like one of them is extra but i think it is probably a common output for the -15V +15V rails
anywys one of those outputs has no continuity but the other trafo is the same and it has continuity...also neither of the pins have continuity with anything on the board so it looks like a broken trace or bad connection ....im hoping its one of those two because i dont know how i would even get a repacement trafo for that shit

>>1927867
lmao I'm a zoomer tho. Manhattan is favoured in situations where noise is important, it's often used for permanent hobby RF circuits, as opposed to iterative prototyping. The ground-plane provides a capacitive reference to all signals, and the lack of connecting traces near one another provides a distinct lack of crosstalk capacitance. If the wires are too close to one another still, it's possible to use some small-gauge coax for connections.

My pic is the OP, btw. The circuit itself was working great, until I discovered the flaws of using a switching PSU. Even with all those caps, there was still a buzz on Vcc that permeated everything and was noticeable if I turned the gain up too much.
That reminds me, I've got a transformer with a couple of windings that would make a good low-noise power supply, if I can find it.

>>1927867
Check ou AN47 by Linear.

>>1927879
i was right for the common output pin ...the number 3 pin is a common one for the -15V and +15V rails and one of the coils (the right one) has no connection ...unfortunately that means the trafo is bad

when connected to an LCR meter the broken coils show 41pF which is kinda big capacitance...the coils connected to pin 3 are a bifilar pair and the big capacitance means it has a long piece of wire coated with isolator as the "capacitive core" (kinda like when an electrolythic cap is rolled up) which means it probably broke off at the very beggining of the coil (the pin leg) , most likely the wire that was soldered to the leg broke off or it had a bad solder joint

unfortunately the trafo is filled with epoxy on the underside (probably why the pin broke off the wire from thermal dilatations) but there looks like there is a "vent hole" near the leg so i hope i can fill it up with flux and heat it up with my soldering iron to try to get some kind of reflow happening but its kind of a longshot ...although considering i cant get another one of them ill most likely try to dig up the epoxy just a bit to try and get to the wire

>>1927456
does anyone use gEDA/gschem? I am on linux and my mouse wheel won't stop spinning, like something is loading, but everything else works 100% perfectly, how do I fix this.

>>1927906
pic rel

>>1927906
download KiCAD and use that ..its actually useful for the most part

Where can I read up on making circuits with microcontrolers robust enough for industrial use? Say as a sensor for a plc in a production plant.

>>1927918
probably whoever is ordering them has requirements. Follow those and you are golden.

>>1927712
>That breadboarding
Jesus Christ, they need to learn how to prototype correctly. That wiring is shit

>>1927912
>KiCAD
I have tried it. The controls make me sick and it is often unresponsive. Also, I got the mouse thing sorted out.

>>1927712
I'm new, but is the point of this post to show how retarded it is that he needed so much extra shit to accomplish a simple sin wave?

>>1927924
thats not a prototype its babbys first wiring ...its fine for a lab job thats supposed to be done in 15 minutes

>>1927928
>he controls make me sick
i agree ...but its the most versatile in my limited experience ..although when i wann do something proper i use altium/circuit maker on a company license when i can

>>1927918
PLC is a controler for industrial use ....although most microcontrollers are robust enough to be used in industry but to be sure just go to your preffered component reseller and choose automotive/industrial in the filter section and it will pop out , usually most of the industrial shit is about power supply rating and input/output robustness , most IC go from -40 to +135 °C anyways

Alright /ohm/ites, I'm in need of some help and really just a good shove in the right direction.
I'm wanting to build a circuit that will generate sound. Not any sound, specifically something that sounds like a car engine that I can change the tone/revolutions on the fly.
The only example I can really find is the "VroomBox" that you install in your car. It reads in the RPMs of your engine and generates the sounds of different cars that can play on speakers.
I'm not looking to build something for my car, but that's the best example I could find. My issue is that for the life of me I can't find a good source/book/whatever on how to generate sounds from scratch using some computer language. I can make sine waves at specific tones, but thats it, I don't know how to make more complex sounds - like a car engine.
I'm quite well versed in using microcontrollers and DSPs, but coding complex audio is the wall I keep hitting. I can easily play back recorded audio, but thats very limited.

>>1927888
jim williams is wild ...idk how an app note can read like a terry pratchett novel and still be the most usefull document

man i miss those days when you could write jokes in the manuals without HR breathing down your neck

>>1927935
you can do that using analogue circuitry but you will need to roam audio synth forums to get all the needed parts and the hardest thing is tweaking all that to get the right tone and timbre ...moving it across a frequency range(acceleration) is trivial

you can do it by using an MCU that reads a soundbyte from an SD card and warping it with some DSP

id recommend googling how computer games generate engine sounds across the RPM range because thats gonna be the most difficult part of it if using an MCU and/or DSP (you will need some audio amp output for the speaker of course but i guess you knew that)

>>1927935
>not sod/ohm/ites

>>1927941
I'd rather do it on a DSP than analog, although I'm not 100% against it. I never thought of loading a sound clip and constantly warping it though, that may be a good direction to follow!
Yes, I'm aware of how to deal with audio once It's ready to hit the speakers. I've designed and built custom amplifiers for over a decade now, lol.

>>1927952
https://scholarsmine.mst.edu/cgi/viewcontent.cgi?article=8574&context=masters_theses

heres a paper on car sound simulation ..you should be able to do it in a dsp

but it all comes down to just how accurate you want the sound to be...most of the time engine sounds are meticulously recorded and thrown into a DSP to interpolate the adequate sound for each parameter(RPM for instance)

a sound such as
https://www.youtube.com/watch?v=2RWrYmA4xKs
can be done by combining one or two waveforms that are controller by a rising (or falling) triangle wave which would mostly be analog way of doing it

otherwise you can do early era digital synthesis
or go more complicated and to this
https://www.youtube.com/watch?v=kpeJdErx5b4&feature=emb_title
which requires software and serious processing power

basically you should set a realistic goal of choosing some kind of sound profile you would contend with and continue from there

> I'm aware of how to deal with audio
mentioned it just in case

>>1927955
Sweet, thanks anon, this is good stuff.

>>1927766
>plugs analog scope directly into 240V mains
Nothing personnel

>>1927986
>Not having high attenuation probes
>Not having high voltage differential probes
>Not having transformer decoupling on your metrology gear

Couldnt be me fren

>>1927901
Poking it with a soldering iron and dumping some flux into it caused it to get some kind of intermittent connection ...enough to get some kind of reading on a LCR meter

That gave me hope and with nothing to lose since the part is most likely not able to be found i tried digging around the pin and managed to get to what looked like a wire end...i managed to heat that and the pin and added solder to the joint ...testing it gave me inductance and resistance values that were correct for a working coil (basically identical as its other pair)

Once it cooled down i soldered it back in place and the thing turned on and worked as it should...im still baffled how something so stupid was the cause of the malfunction

>>1927930
I assumed it’s a resonant driver, and a reasonably powerful one too, judging by that big capacitor, coil(?), and PCB with large components on it. Probably something like an induction heater.

Even if it isn’t, if that’s a closed-loop AGC connected to a normal sine wave generator that can have its amplitude adjusted electronically that would be pretty neat and possibly take that many components. I personally stay away from some generators and prefer to shape squares and triangles.

>>1927935
No dude it’s “ohmlet”. Cue eggposting.

>>1927952
You’re familiar with Fourier theory, right? There will be some method of adding up harmonics of integer multiple frequencies (with differing amplitudes and phases) in order to create the baseline waveform (non time varying). It’s probably easiest to use sine waves for this, but arguably it might take less memory to use a triangle wave or something else mathematical, or maybe even a more arbitrary waveform stored in progmem. That will get you 90% of the way to a good-sounding engine noise, but it may sound pretty monotonous. Which is why time-varying aspects (constant-rate and/or rate proportional to rpm) like virtual VCAs and VCFs will come in handy. Maybe even more exotic effects like you’d get with guitar pedals or modular synthesisers.

If my intuition is correct, you’ll be able to effectively have a virtual modular synth (with fixed effects and their parameters) within a medium-size MCU, at least according to progmem. Not sure about ram, but I suspect you’ll be in the clear so long as you don’t require storage for delays or whatever.

I’d spend some time looking at engine sound waveforms to split them into the shape of the wave itself (static) and how the shape or frequency or phase or amplitude changes with time and with increasing rpm (dynamic).

>>1927928
just change the keybinds bro

>>1928018
Nice work anon.

>>1927941

once had gig with an elevator company that wanted a talking elevator. at that time, long ago, if you wanted some affordable EPROM chips, you essentially had to choose 16K ones. not mega, not giga, just 16K, which is like 2 seconds worth of uncompressed audio.

anyway, now that you can get 16gig SD cards for the same price, it would seem the easiest solution would be to just record a whole bunch of samples from, say, a racing game and use a small micro to pull them out as appropriate.

>>1927500
Try to start by building the simplest usable form of the project. Then once you try it out you'll have a better idea of what features you really need to add.
that also encourages you to design it to be modular and expandable.

>>1927936
that one with baby bottles for rating circuits was pretty entertaining. I hate how TI makes such bad documents and datasheets nowadays, full of errors and kinda weird to read. But quality vs quantity I guess

>>1928118
don§t you need a couple Mb IN the MCU to read from SD Cards? Because of the size of the adresses and pages etc

>>1928188
not really no ..you get a soundbyte and dump it as it comes since its all serial you just spit it out as it comes in

woops i ripped of the saftey device. ah well will take it off.

>>1927786
how to make a BJT amplifier with high gain at 10m
Cbe to ground keeps eating my signal

>>1928220
Cbe as internal capacitance or the emiter degeneration capacitor

you know one might sell all kinds of little parts on amazon.

>>1928118
The goal was to learn how to generate the audio, or at a minimum, properly modify it in real time. Yes it would be much simpler to play back from 100's of samples, but I'm using this as a learning experience.
>>1928188
Not nearly that much memory. I can stream 16-bit 44.1khz audio with less than 1k memory. Using dual-channel DMA memory to input data from an SD card from UART.
>>1928092
Yes im familiar with Fourier, I have a few books written by an EE professor that were published not too long ago. They are the absolute basic start to DSP with audio. I just needed a direction to generate engine-like sound that can be manipulated real time.

>>1927500
This anon said it best >>1928138 Break the project down into smaller, functional pieces and bring them all together at the end. I like to build modular units for this very reason.
That way, if you build something simple like a nice 5V+ supply for digital, you can even build one again in the future for another project, quick and simple.

>>1928072
It's a current source inverter control by C2000 MCU, my final year project

>>1928269
whats the switching frequency ..thats choppy as fuck and is most likely throwing EM all around the place ...do filter it a bit if you can

>>1928271
Yes it still not filtered yet.
Fsw is around 8k-10k, should have use bigger inductor.

>>1928273
ah thats pretty low switching speed ..modern switchers work at 200khz and above

but it should be fine once you filter it properly

Any idea why my amp still has sound, even when the volume pot is turned to 0? When I turn it up it gets louder, but on 0 I can still hear the music playing from my phone. The pot is 2.2kΩ. Input -> yellow wire -> potmeter -> red wire -> amp pcb.

>>1928303
If you are smart enough to understand stuff without circuit diagrams then you are clearly above us mere mortals

>>1928308
I built this circuit with the same PCB on as on the image. The the yellow wires connect to the potmeter, from which the red wires go to the in 1 and in 2.

>>1928310
>>1928303
most likelyyour potentiometer does not go really to full 0 resistance since that would be a short circuit over the slider part ...get a potentiometer with a switch off detent (or put in a serial switch ) )

>>1928303
>Input -> yellow wire -> potmeter -> red wire -> amp pcb.

this kind of description is just pure gibberish. draw the fucking thing.
it kinda sounds (from the gibberish above) like you have you have your reds and yellows juxtaposed. i.e. the signal input always goes on the outside extremity, and the signal going to the amp goes in the center.

>>1928303
>Input -> yellow wire -> potmeter -> red wire -> amp pcb.

this kind of description is just pure gibberish. draw the fucking thing.
it kinda sounds (from the gibberish above) like you have you have your reds and yellows juxtaposed. i.e. the signal input always goes on the outside extremity, and the output signal always goes on the center pin.

Retard question from someone who can't into electronics.
I need some capacitors for a motherboard and they're rated 3300 uF 6.3V. Problem is I can't find these in stores in my country. Can I use capacitors rated for a different (higher) voltage instead?

>>1928344

you can always go higher. same way a chair rated for 300 pounds can substitute for one rated 200 pounds.

>>1928344

you can always go higher. same way a chair rated for 300 pounds can substitute for one rated 200 pounds.
just know that the higher rated caps will be taller or fatter, or the leads will be further apart, so the fit around the crotch may be tight.

>>1928353
Ah, I see. Found some 16v ones, I hope they'll fit. Thanks for the help, anon.

>>1928225
I'm not sure, all I know is that high current goes into the base, but little amplification happens. Adding an emitter resister and/or RF choke fixes the problem, but then it kills my gain.
Currently working through my ~10th "design a bjt amplifier" tutorial, idk why they never work. RF fuckery I guess.

>>1928375
>Adding an emitter resister and/or RF choke fixes the problem, but then it kills my gain.

one trick is to add a cap in parallel to the emitter resistor. the resistor determines the DC gain, but the cap makes the AC gain larger than the DC gain.

>>1928215
I think I can rig one.
side question, I have a computer taken apart that powers up sometimes. Is a safety going off our is it shorting?

>>1928383

could be one of a trillion things. for example, for a while i thought my computer was dying, when in fact it was just the power switch being intermittent. replaced it with an external switch coz the front panel is a bitch to remove.

>>1928389
fellow pushbutton bro

>>1928389
>>1928393
Get on my level

>>1928383
what do you mean it powers up sometimes ...is it powering up by itself at radnom times

or do you mean when you push the turn on button sometimes it wont turn on at first

>>1928398
now this is some professional niggery

>>1928398
Nice.

>>1928398
Sexy

>>1928375
What transistor are you using? It should have some gain-bandwidth-product or similar feature, 10MHz is getting up there for some BJTs. You might also have the issue of your signal's output impedance being too high, in which case consider using a JFET instead.

Hi /ohm/, I'm this anon from here.
>>1918677
>>1918679
I have got voltage readings for the CNC and slide table, the CNC schematic being in this image here.

tl;dr since it's been a while
>CNC controller lights up and engages with the CNC but the CNC won't turn, no faults, everything should work but the controller is probably wrong given it's not a variable PWM signal
>Slide table faults when powered, don't know the cause of the problem.

The related picture is the schematic for the CNC. Trying to get it to function but just don't know the problem. Might just be the controller and everything else functions.

Would get the original post but Warosu is down

And this is the slide table. Faults on power.

Appreciate any help. Just can't get this stuff to work which is frustrating.

>>1928402
i fixed that, now no display working.

>>1928429
no signal, checked monitor it's fine. the monitor is a little funny let me try mouse, kek

>>1928225
Get rid of your collector resistor and whack in a current source. Current MIRROR, two-transistor, emitter follower, CRD, whatever, anything but a resistor. High output impedance = fuck ton of gain. If you need a low output impedance tack on a buffer after the gain stage.

Active loads are amazing. Don't waste time with bypassing the emitter, just do it like OP-amps do!

>>1928428
>>1928427

your voltage readings are useless coz it's obvious you dont know how to use a voltmeter. you need to look up the very basics of it. like this video https://www.youtube.com/watch?v=_lDU1ORX7Cg or others in the same vein.

once you're reading 24Vdc out of the power supply and 5.0Vdc out of the arduino, you'll know how to do it.

>>1928442
Alright thanks. Will report back when I'm doing it right.

What kind of material/tubing is used to for something like USB cables, and where can I find some transparent versions of it?

>>1927757
because typically 1GHz DSO have shit sample rates like 10-100Msps in which case analogue blows it out of the water because there isn't sampling. Once you get a *good* DSO then of course, that's better than analogue, but in the low range of specs, you can get so much more features for so much less costs going analogue.

>>1928449
just as a reminder: make sure you're using both probes to measure, and make sure the black one is always on a test point or known ground- all the measurements need to be in reference to something (ground ideally unless you know what you're looking for)

>>1928469
>because typically 1GHz DSO have shit sample rates like 10-100Msps
do you mean like when you set it to longer timebases or in general?
because the second one makes no sence since it needs a lot of samples to even be able to get to that bandwidth and zoom in to the lowest timebase ...also even if you mean the first one you sitll can force sampling to max on bigger timescales if oyu want ...at least the keysight and pico scope i use are able to ...althoug hyou nned to wait longer for it to sample it all

Is there a rule of thumb for what value resistor to use if I'm making a voltage halver?
It's gonna be feeding into the inputs of a few CMOS chips that should only pull 2mA or so each.
10K a good way to go?

>>1928469
>>1928472
cont.
>get so much more features for so much less costs going analogue.

this i absolutely agree iwth you ...the price performance of analogue scopes has been crazy this few years and for most people that dont do it professionally its an amazing thing ...i just hope it does not start inflating in prices because of some other fanboys or gatekeeping indiviuduals

>>1928473
do you mean pullup resistor?

i yes then yes 10k is standard

>>1928461
PLEASE SOMEONE HELP MEEEEEEEEEEEEEEEEEEEE

I have no idea what to search. Generally only heat shrink tubing comes up

>>1928473
you can do the math: V=IR ; R = V/I = 5V/.002A = 2.5k

you can use 10K but it will pull less than 2mA, which is usually OK if you're just trying to pull up/down a pin. I don't think you mean voltage divider, but if you do, you can do the same math to figure out the the resistance needed for your current

>>1928461
https://www.performancewire.com/insulated-wire-protection/
insulation materials are usually just chosen to be as cheap as possible while retaining their quality , and the cheap part is especially true for low voltage (less than1kV)

just google transparent insulation wire(one strand two or more , and what gauge you need) spool or something like that

>>1928473
i think, iirc, the output resistance of a voltage divider is R1||R2.
Basically, pretend all impedances coming out of the output node are just a short to GND (i.e., replace with cmos' output pin with GND), then sum all the resistances coming out of the node in parallel/series as appropriate.
Is that right?

>>1928478
No, I mean a voltage divider that splits the voltage directly in half.

I've a board that uses a bunch of differential input signals that go to CMOS chips that change them into simple 5V logic signals for the microcontroller.

So basically for each differential input pair, if the inverting input is higher than the non inverting input, the output is low and if it's lower the output is high.

So I was basically make a voltage halver to give me a 2.5 volt reference to tie the inverting inputs to and then I can just pull the non inverting inputs to 5V or to ground to toggle the outputs.

>>1928472
Those 1Ghz bandwidth are only really useful for repetitive, digital signals; if you're trying to sample a true analog waveform using 100Msps then you will be in trouble since you'll likely miss what you're looking for, even with the higher bandwidth

>>1928479
you are on a very slow board let alone thread ...dont cry or bump if no one anwsers oyu in such a short time ..sometimes an anwser can take up to a day ...if its really important and you need it fast its always better to just google away untill you find something or just ask your local electrician gear reseller

Where do you get 18650's that aren't ass rape?
I want to buy a few of the cheapest aliexpress flashlights possible so I actually have some lights around that are visible in daylight, but the batteries from chinkland are probably shit and battery retailers rape me with shipping.

>>1928481
Thanks!

>>1928475
if you look at ebay, I think it's already catching on; and definitely has on my local craigslist, even shit 100MHz scopes are selling for like $200

>>1928484
Might want to lower the resistances if you want to pull 2mA current in that case; see above calc you probably want like 3k/3k or whatever

>>1928479

google says "The various insulating materials used in manufacturing of cables are rubber, VIR, paper, Polyvinyl Chloride (PVC), Varnished Cambric, Polyethylene, Gutta-Percha, Silk, Cotton, enamel etc."

as for clear replacements, you can get (vinyl) tubing from the plumbin section at the hardware store, or the pet store (used to aerate aquariums)

if you want free: pretend you cant breathe, and the nice EMS guys will put a mask with a long tube on you. or, hang around hospitals, and pick up the saline drip bags from patient's rooms.

>>1928484
then you need a voltage divider with a ratio of 1:1 ...and the resistance sizes can be 1k:1K or 10M:10M ...if its about current limit then use ohms law U=I*R...R=5V/0.002= 2500ohms

so anything 2.5k or above is fine

>>1928486
>>1928494
ty

I making a power supply for a project that I thought just needed +15V, -15V and +5V so I basically have a transformer stepping mains down to 15VAC, half wave rectifying it to get a positive and negative and using a few filter caps, passing them through a 7815 and 7915 to get the +/- 15V and then passing the +15V through a 5V regulator to get my 5V.

However, I've just realised I need a 24V line too.
Is there an easy way to get the 24V from the -15V to 15V rails but using the same 0V ground or should I just go get a 24VAC transformer and add a 24V regulator?

>>1928493
>>1928495
Cheers senpai

>>1928493
i believe he used that as a max limit ..cmos is still voltage controlled and lower currnet is better for protection (up to a point of course)
>>1928489
rip newbies then i guess ...my local second hand shit still sells them for like 50$ for 100mhz tek-s

>>1928487local electronics shops ..unfortunately shipping rates fuck everyone up the ass because private shipping of lithium batteries is grounded to land travel only and will be shit until further notice

>>1928473
Yes. The divider quiescent current should be at least 10x the load current. 2mA load current means 20mA divider current. I don't know what your source voltage is since there are several different standard CMOS voltage levels however the total divider resistance is: Vsource/(2*[I(div)+I(load)]) <---(assume I(load) ~ 0). This should work out to a divider with two 125 ohm resistors for 5V CMOS, now that said...CMOS gates should draw way less than 2mA in practice though. Don't mix up input current with quiescent device current, two totally different things. CMOS input will be under 1uA typically so 10k should be fine.

>>1928498
if you are not gonna load the trafo more than rated with current then just connect to one of the coils in paralel and add a boost converter


if yo uare not sure then do a separate 24 V line just in case

>>1928484
TL431
LL
4_4
3__3
1___1

>>1928487
try in some vape stores some use 18650s, idk if they have higher prices there tho

>>1928498
>Is there an easy way to get the 24V from the -15V to 15V rails but using the same 0V ground

it's doable, but not easily. essentially you buy, or build, a DC-DC converter that includes a transformer for isolation.

>>1928509
>>1928501
What IS a good price for them, what are decent ones? Are they actually dangerous, or people just retarded?

>>1928536
>What IS a good price for them
as cheap as you can get it from reputable sellers

try asking around RC car shops/forums (the racing ones), RC plane ...try asking also lapotp repairmen, vape shops local electronics ressleres etc

>Are they actually dangerous, or people just retarded?
people are retarded but retards set global rules and the same retards that dont allow you to take liquids on a plane also said they dont want "volatile" batteries on them either

I'll roll for a project, I guess? Pretty bored right now.

>>1928552
Like 4 or 5 dollars for a sony or lg cell? I was looking here, the shipping isn't awful but I don't plan on buying more than maybe 2 or 3, so it ends up being a large percentage of the order https://www.18650batterystore.com/18650-Batteries-s/106.htm

I plan on just using single battery lights, I don't see why they'd be any more dangerous than a regular AA or whatever besides lithium in general being more reactive. Is it just people using really really shitty chargers causing problems? I only have 1 device with a removable 18650, it's just a flash light with the micro usb built into the cell, I leave it overnight and it's fine so I don't know what the fuss is about with exploding batteries or whatever.

>>1928556
anything oredered in small quantities for hobby uses will not seem like a good deal because it isnt lol ...but if you wanna make projects just spend the money and do what you want ...or find an old notebook with a working battery and salvage that ...its just a battery bank with multiple lithium batteries in it

the exploding iphone and samsung galaxy craze caused a worldwide ban of lithium batteries on flight shipping...they are much more reactive than most batteries because most are just corrosive and even the ones that are simillarly reactive never got the bad publicity so thats it

basically the whole thing happened because requirements for batteries in certain requirements surpassed the technology of making them and the chargers required to charge them safely ....nowadays lithium batteries are made very robustly and the chargers have never been better with multiple failsafe points but the damage has already been done

because arbitrary statistics that govern certain risk factor mitigations are used when deciding things like have been written now its permanent untill some company decides it costs too much to ship over ground and lobbies for airfare to return (which most likely will not because they just offload the cost to the end user and suffer no penalties)

its a wonder that some people of certain racial ethincities are even allowed to board planes considerg how stupidly these government regulatory agencies decide these risk mitigations depending on statistics

>>1928552
This, but ask the RC general here on /diy/. That said, they mostly use lipos, not cylindrical cells, since lipos can have much higher discharge currents. One reputable lipo seller on ali is CNHL, they’ve got pretty good shipping times too, think mine arrived in a couple of weeks. Maybe they sell 18650s?

>>1928555
Well, gotta do something with a 555 now don’t you!

>>1928555
555 trips means you get to design your own clock gen like the 555 timer

>>1928573
>>1928574
Sound interesting, I'll look into it. Guess I could design a 555 timer from scratch, or a variant of it. Maybe H&H has a chapter on it.

OP here. I’m thinking of working on a better project list, with sections to choose from for a variety of subfields (MCUs, discrete digital, audio, RF, etc) and difficulty levels (from a digital clock to a PID controller to an induction heater). Anyone have suggestions?

>>1928581
2:1 Vackar oscillator
earth's field NMR
ESR spectrometer https://www.youtube.com/watch?v=OnYT6L6XdIg
Sound effects: delay, reverb (3-line), chorus, sub-octave, spring reverb
temperature controller sawtooth
Hex-schmitt drone oscillator

>>1927712
is this UNLaM in Argentina?

>>1928583
Now that’s some neat looking stuff! I was thinking about getting a handful of those kinds of high-level projects (perhaps 3 per subject) and break them down into subcircuits. Then I’d make some medium-level projects out of those, then break them up further to make the entry-level projects. Say, for digital logic there would be “make a 7-segment decoder in discrete logic” as an entry-level project, leading to “make a digital clock” as a digital mid-level project, or “make a Geiger counter” as a mixed mid-level project, then something like a hardware encryption key or an SDR further down. With freedom given how to approach CJ the project and whether to make it out of lower level projects at all, of course. The project hierarchy would be more for the purpose of guiding the knowledge development than for anything physical, at the very least I can’t imagine anyone making any kind of counter + display out of discrete logic unless they’re mad.

But I think I’m too much of a brainlet to understand how those circuits you mentioned are meant to work, at least not without studying some circuits and functional principles first.

>>1927723
tfw I'm currently working on my first pcie1 card
and I reached a point where I think you're right, kek

When it comes to speakers, what determines a drivers impedance? I get that it changes with frequency etc. but what actually sets it? Type of core? Turns of wire? Coil wire thickness?
How does it actually work? Maybe I'm bad at google but I can't seem to find any solid write ups on this, shouldn't this be common knowledge?

>>1928751
maybe you have more luck looking up how transformers are calculated

>>1928749
>I'm currently working on my first pcie1 card
I was just thinking about this earlier. The actual connector interface is relatively trivial if you can make PCBs, but what's the protocol like? Looking at the pinout it reminds me of RS-232 with its CTS, RTS, DTR, DTC, etc. pins that nobody uses. At least it looks synchronous, which probably helps. Do you actually have to use all of the pins? Can you use different clock rates? Just hooking one up to a high pin-count MCU that you can program to do whatever might be neat. Or an FPGA if you wanted to use it for high-speed shit, which you probably would.

>>1928751
Impedance of any kind of coil is a function of inductance and frequency, and is complex. Look up an inductance calculator on hyperphysics or wherever, and look up the equation for inductive reactance. There's also the DC resistance to add into the equation. The idealised so-called "impedance" of a speaker driver will be the average impedance around its intended operation range, and hence will determine the approximate current for the voltage driving it in normal operation.

So I just got into trying a bit of electrical hobby stuff. So far most things have been a success.

At the moment I'm trying to power a fairly long LED strand. I'm injecting power but it still isn't really making it to the end. The strips are 5v ARGB, the power supply is only 5amps. I think that is the issue as the 5amp I tested with two strips (10m) and its fine, but I'm using 3 strips. Would just getting a higher amp psu (10amp) work?

>>1928832
5V strips really shouldn't be very long. Measure the resistance from one end to the other along one wire, see what you get. If it's 1Ω, then you're gonna get 3V drop across it at 3A, which is gonna stop the LEDs from conducting properly, and hence bring that current back below 3A. Instead of making a chain, put them in parallel at one end instead. Or run thicker jumper wires to the middle.

Your PSU is outputting 5V (presumably, that's also something to measure) so regardless of how many amps that PSU can push, it's not gonna somehow light up all the LEDs if the ESR is too high.

>>1928837
Its not one long strip but many small ones forwarding their data to act as one, which that part works. A separate thicker wire is run along side to splice in power to each section, but it died out as I got to the last few meters. That is why I was wondering I was trying to power too much from one small psu, it would normally be one used for a strip not many. More amps going into the power wire would mean more arriving at the end after resistance eats into it?

The strips can accept power in both directions, which works fine and the layout is a loop so the start and end are next to each other. So my thought was it just doesn't have enough juice to power them all.

tldr I'm not hooking it at one end of a giant strip and hoping it makes it to the end, power is carried by better wiring, but its a small psu.

>>1928840
Just measure the damn voltage at different parts of the strip to figure out what the issue is. If it's those wanky digital RGB LEDs you're talking to, then they can be a bit particular about noise and such and may not accept long unshielded wires. Try turning off all the LEDs and turning on one at a time. A circuit diagram might help a little. What gauge is the thicker power wire?

If it's lighting up the first LEDs but not the last ones, then your PSU is working fine. If your PSU couldn't handle the current, then all the LEDs would probably go dim since they're all in parallel. Could be both issues though, so measure the PSU's output voltage (it will sag if it can't produce enough current) under different conditions.

Simple question, I've been looking for a logic simulator (tinkering with 7400-series), and logisim looks like a decent fit for what I want to do.
There seems like a dozen different forks of it, and no clear reasoning for each. Is there any particular recommended version (or benefits of each)?
I'm open to other program suggestions as well if it's a bad choice. My only past experience was years ago with cedar logic, which I found limited and clunky for anything remotely complex.

>>1928751
Short anwser all your questions is unironically yes

>>1928853
http://www.cburch.com/logisim/
2.7.0

>>1928853
>>1928882
2.7.1 is the latest official version, but it's from 2011. There are some forks that seem to just be foreign language versions, but the main forks seem to be as follows:
>Logisim Evolution
>Logisim holycross (getting some T Davis vibes with that name)
>Logisim by Joseph Lawrance et al.
>logisim-iitd (pajeet)
>Logisim for the CS3410 course, Cornell University
Looks like evolution is likely the most advanced as it's actively trying to integrate features added by the other forks. Read the readme on their github:
>https://github.com/reds-heig/logisim-evolution
In my opinion Logisim is one of the best digital logic sims out there, so I wouldn't bother looking for something else unless you have particular requirements that Logisim doesn't meet.

Maybe I should go for Evolution, which I didn't even know existed until you asked the question. My old version of Logisim (which was still old when I downloaded it 4 years ago back in uni) stopped booting after an OS update or two. Or maybe it was a java update.

Also I'm gonna add it to the OP because somehow it isn't in there.

>>1928832
>>1928840
Congrats on trying to fiddle with electrical shit

Now go and buy a digital multimeter (get a uni-t for 30-50$) and a linear power supply with a voltage/current display (ebay 30-50$)...and look up what ohms law is, the wire resistance formula, kirchoffs law(voltage and current laws), how a diode works and what constant current and constant voltage mean and how to measure voltage and current with a multimeter

Once you did all that (the linear power supply is optional rest of it isnt) measure the current draw of your led strips and the voltage drop on each connection

if your current was limited all your diodes would go dim altogether, your voltage has dropped over the long wire and parasitic impedances below the threshold voltage of the led-s that dont turn on..but to be absolutely sure of either one of those theorues you need to measure it, there could always be a split wire in there too

>>1928885
Ok I installed Evolution and it seems to work fine, but a few caveats. First of all, I had to install OpenJDK version 15, no big deal assuming that didn't mess up anything else. But I can't just click on that jar file to run it, I have to run
>java -jar logisim-evolution.jar
in my command terminal. Which is a bit inconvenient, especially since I do 99% of everything without a terminal window open.
I'll work on getting a script file or something to do that for me. May differ for your OS.

At the very least, it still works better than 2.7.1, which won't even boot.

>>1928751
Impedance of a speaker coil is a combination of the coil resistance and coil inductance(Z=R+XL where z is the combined impedance , R is the wire resistance and XL is the inductor impedance and is equal to 1/(2pi*L*f)...usually for general purpose uses most LCR meters test at 1khz unless otherwise stated

The inductance (L) of a coil is dependant on the number of turns it has, the diameter of the coil and the magnetic permeability of the medium inside the coil (if it has an iron core in it or only air)
And the wire resistance is dependant on the wire length its cross section and material its made of

Also im extremely bored to be willing to type all this out since everything i just stated could be found on the first pages of google search or any begginer book of electronics ...but i guess if there were no stupid questions in this thread there would be no posts either

>>1928901
>Obligatory werks on my machine

Idk i use winblows and have no problems with either version of it

I'm trying to get a FT230X-S on my PCB to work (I'm implementing a serial interface via USB type B)

I may have fucked up my solder job, but more likely I fucked up copying the schematic (original is the one on the right).

Does this look correct? Am I missing something? Did I fuck something up? Troubleshooting this is a real pain. (first time doing this)

Thanks in advance.

>>1928901
>I'll work on getting a script file or something to do that for me.

naw, nigga. you just create, or copy, a shortcut and modify the Target, and Start In boxes. for Target you put in your cmd line, for Start In, you put the folder of the Target.

>>1928995
>USB D- connected to USBDP
>USB D+ connected to USBDM
this signals are not interchangeable, doing so won't allow USB comms
what was your problem?

>>1929033
that was probably my problem. I just totally missed that.

apart from that, do you see anything else?

>>1929080
its basically all copy pasted anyways so it all looks fine as it is except the data pins

can i see the PCB layout? ...that could most likely be tweaked a bit

>>1929095
I just deleted it to start again, I will post once it's done, later this evening.

>>1929097
Ok then just keep in mind
>Decouple caps as close to the pins
>Usb data traces to be same lenght or as close to same lenght
>The resistors for the signals should be paralel so they are at same lenghts in the signal path and not one after the other
>Signal traces should be as short as possible

>>1927712
Looks fine

I bought the relay board hoping to PWM control the cob led as a way to dim the led. I just wired it up and the voltage drops to 75V at the output of the relay.
*The cob hooks up to mains. The really is supposed to be for AC.

>>1929108
Any help would be appreciated.

>>1929108
Circuit diagram of what you are hoping to do. ANd btw, using relays to pwm anything but a large oven will make A LOT of noise

>>1928999
not windows
nice trips

>>1929108
PWM with relays is a bad idea. COBs are also kinda shitty because of their flicker. And don't run that thing for long without a heat-sink.

>>1929113
they are solid state relay they make no noise
but yes using a relay to pwm is retarded ..why not just take a mosfet and pwm that

>>1929121
Most SSRs are significantly slower than MOSFETs, making them bad for PWM, but they do AC while MOSFETs need to work on DC.

Personally I'd just rectify mains with a full-bridge and a few big capacitors (100µ or larger), and feed the COB that DC, which I'd PWM with something like an IRF840. Problem is, using a full-bridge causes that 0V to ride the lower half of the mains wave down to -170V, meaning your PWM circuit will need to be otherwise floating and somewhat noise-immune. Not a big issue though.

Also note that I've tried to run a COB off rectified mains before and might have run into an issue or two, when it blew a breaker. Was probably just my shitty wiring, but you never know. The filtration capacitors aren't necessary as it will run just fine without them, but I'd use them to get rid of the flicker and limit the maximum duty-cycle to ensure it doesn't overheat with the higher RMS.

>>1929121
yeah whatever, just post your circuit board
>>1929126
>Most SSRs are significantly slower than MOSFETs,
pipipi popopo it's ilumination, switching speed doesn't need to be high.

Also are your SCRs based on triacs or something similar? if so, ask yourself it just "PWM control" as you described even makes sense.

>>1929132
if just*.

>>1929132
>switching speed doesn't need to be high
If you can see the 60Hz flicker on a cob that isn't being PWM'd, what do you think <100Hz PWM is going to look like? When I say slow, I mean 10s of ms slow.

Also pretty sure SSRs are meant to work asynchronously with respect to mains.

>>1929136
>Also pretty sure SSRs are meant to work asynchronously with respect to mains.
You need to read the datasheet and whatever the manufacturer gave you. Some of them are FETs, some are SCRs some are some other shit. That is why the goddamn circuit is better than a blurry pic.
A fair bit of the AC ones are indeed triac based and turn off with the zero crossing.
>If you can see the 60Hz flicker on a cob that isn't being PWM'd, what do you think <100Hz PWM is going to look like?
Pretty bad probably, I am assuming he won' go that low but
>fucking circuit diagram and component names

shit markings on resistors makes me feel bad

>>1929132
>yeah whatever, just post your circuit board
im not the poster that put up the pic ...i was just pointing out that those are not mechanical relays

>>1929113
>>1929120
The cob I would use does have a heatsink and it would be for a grow tent so flicker would potentially be beneficial (according to some studies).

>>1929168
Sorry, I mislabled the picture. I have it set up positive from cob to relay, and positive from relay to mains. And mains negative directly to the cob.

>>1929168
wait its an AC ready light ? ....why didnt you just get a 2 dollar ac dimmer and call it a night ?

>>1929185
I was hoping to control a few different lights with this relay board and as an after thought considered it using it to dim the lights with PWM. I think getting a dimmer might be the way to go. I still want to know why I'm only getting 75V after it goes through the relay though.

>>1929191
Can you show on your circuit where you put your probes at so i can be sure what you measured exactly?

>>1929168
Also post a high quality picture or part number of the relay ..i wanna check something

>>1929201
I tried a different channel and it worked! I guess that one relay is no good because I went back and tried and im still getting the same result. I know at least one of the relays works. I appreciate the time anyone spent on this problem for me, Sorry I didnt trouble shoot it better before I posted.

>>1929214
Yeah, if there’s a voltage drop greater than 1V away from mains or GND then it’s gonna be dickered, and probably pretty toasty too. That said, if it’s a synchronous dimming then you’ll be getting some funky measurements just using your AC measuring mode. If your DMM isn’t true RMS then you’ll get funky measurements on it regardless of PWM method.

>>1929214
at least you posted a real project and shown you actually are trying to do something
considering most people come in here and say hurr durr whats ohms law kind of meme and do nothing and just as retarded questions that go nowhere

>>1928341
This

>>1928303
Pot wired wrong, i see that you ran those yellow wires from your rca jack to your pot wiper, switch the red and yellow wires on the pot and it should work better

>>1929101
what's the purpose of these 470ohm resistors on the signal lines anyways? I've never had to use them on, for example, the TX and RX lines of a TAG connect. How is the ft230 chip different?

>>1929268
For signal integrity and impedance matching

>>1929268
>>1929275
Usb protocol usually requires some resistance on the data wires to set modes and protocols ...most chips have that built in but i guess this one either doesnt or they just put that as a general use signal integrity thing ...if the chip has internal impedance settings then its basically not nescessary to have the resistirs if the traces are very short but it does not hurt to have them just in case anyways ...the capacitors are also optional but are there for signal integrity too


If someone has more detailed info about it or if in wrong id like to know too ...what i said is a bit limited tho from when i was doing some usb based battery charers and power delivery so i might be wrong

>>1929275
>>1929281

thank you very much

>>1929281
I thought those resistances for setting modes are solely for the case that you’re not transmitting data with them, in order to communicate charge current. But of course you’re going to need to communicate charge current even when you do need to transmit data, so either the resistors are used in both cases, or the device being charged needs to be able to listen to both USB info and read those data line resistors. I’m guessing some advanced USB power management ICs will have all that shit on their datasheets.

That’s all USB 2 or below though, USB 3 (at least type C) does all that shit with proper communications because of negotiating different voltages.

Just picked up a E3630A power supply, its my first. How am I supposed to adjust amps on this?

>>1929437
https://www.keysight.com/us/en/products/dc-power-supplies/bench-power-supplies/e3620-series-bench-power-supply-35-50w.html#Resources

bottom left.

Literally google the manuals for things you buy. It's that simple.

>>1929440

" The current limits are set by adjusting R63 in
the V1 supply and R34 in the V2 supply (see the schematic diagram)."

presumably you gotta open it up to vary the current limiting. not what you expect for an $800 unit.

>>1929440
Not the right model, but it might be the case. I got it from a junkyard.

>>1929450

>>1929440
>Literally google the manuals for things you buy. It's that simple.

I'd like to add to that, read the manuals of things you want to buy BEFORE you buy them.
If you wanted a power supply with adjustable constant current, you bought they wrong one.
Don't rip on Keysight for this one. They made the right product, you just bought the wrong product.

>>1929474
no, its a shit product

>>1929437
This one?
Sounds like >>1929450 is correct, it's intended to be used as a voltage source without current limiting other than to protect the PSU itself.

>>1929528
not him but what does the COM pin does?

>>1929532
That's the 0V rail for the PSU, while the black ground post on the end is the mains GND. Which can be referenced to COM or one of the other pins, or left floating so long as the voltage between them isn't greater than ±240VDC.

>>1929437
Imagine spending 800$ on a thing you cant use

There is a reason begginer shit is usually cheap

>>1929572
according to a deleted post he nabbed it from a junkyard (>>1929458)

also what kind of fucking ripple rejection and absolute stability is that thing capable of to deserve a pricetag? wouldn't be surprised to see an ovenised voltage reference or some shit at 800 fuckos.

What is the purpose of this circuit? Level shifting? They connect to a microcontroller on one side and input/output(?) pins on the other. The transistors are labeled 337f.

>>1929581
Looks like a level shifter to me, one of the bidirectional ones. Funky MOSFET model though.

You guys got any good resources on pcb design? My current project isnt particularly complex, nor are there any fast data lanes, just a lot of components to fit in a small space.

>>1929604
Printed Circuits Handbook
Clyde F. Coombs Jr.

its a big ass book but it has everything you could ask for and it shows how a lot of the things are made and what considerations are take in account for each step

also when doing certai things you can search for application notes where TI for instance has a lot of design rules/recommendations for high power dissipation board desing
just type in what you need like "power PCB design app note pdf"
or "smd pcb design app note pdf" , "signal trace routing for PCB app note pdf" etc

Can someone please point me towards some good opamp circuit resources?

>>1929667
"Texas Instruments - Op-amps for Everyone"
"Texas Instruments - Analog Engineer's Circuit Cookbook: Op-amps"
both should be freely available but I have them both in here
https://mega.nz/folder/xT5C2AhA#KEvjWz3WulwHOtuhRrDr4Q

>>1929677
Can you share your full collection plz

ordered the breadboard, and i'm actually gonna learn it!

Got my vacuum pump motor cleaned electrically it appears to work correctly except the motor starts weakly and will run in either direction. It seems to work fine when it gets up to speed. I read in some other forums that it might be the capacitor screwing things up. I tried to measure its resistance with my voltmeter, but I get wonky readings, probably the capacitor is huge. Is it a safe bet that my motor just needs a capacitor?

>>1929800
Some pictures. The capacitor, the motor specs, and what I think is a relay.

>>1929802

>>1929803

>>1929800
>>1929802
if you turn on AC electric motors without a zero crossing controller your motor turns in the direction depending on if the voltage period is in the negative or positive side ...also im guessing its a three phase motor thats converted to a one phase voltage (the capacitor is used to do that)

its usually normal for those kinds of motors to start up slow and once they pick up speed they get to nominal power

>>1929809
Then it seemed to be working correctly aside from the random direction. Can I assume that the capacitor is blown and that's why it's starting in either direction?

When I tried starting it while it was attached to the pump, its starting force was too weak to overcome the pump. On its own, the motor would start slowly and then work normally, although it went in either direction.

>>1929809
>if you turn on AC electric motors without a zero crossing controller your motor turns in the direction depending on if the voltage period is in the negative or positive side ..
What the fuck you are talking about.
>>1929817
yeah from what you described it seems like the cap is bust. The capacitor is what makes this kind of single phase motor start correctly. once it is turning it behaves like a regular induction motor. (even if you start it with your hands)

>>1929817
SUCCESS!

I discharged the capacitor and it works now, I think. The motor starts immediately and in the correct direction. When connecting it to the pump, it pulls a vacuum.

>>1929853
>The capacitor is what makes this kind of single phase motor start correctly. once it is turning it behaves like a regular induction motor. (even if you start it with your hands)
I second this.
The capacitor provides the starting torque by shifting the phase of the AC applied to the starting winding, approximating a rotating magnetic field that pulls the rotor along in the correct direction. In some motors, the capacitor is switched out once it's up to speed.
Since this one is powering a vacuum pump, I'm guessing the capacitor stays in the circuit for better torque.

>>1929807
That looks like a thermal cut-out. Breaks the circuit if the motor gets too hot.

Either the cap is bust, or one of the connections from the cap to the motor is broken.
If you want to measure the cap, make sure to take it out of circuit. You should try to measure the continuity of the starting winding too, if it's broken, it could cause the same symptoms.

>>1929872
oh good. Maybe you had a bad connection that got better after you took it apart and put it back together again.

So i have this shitty chink led dimmer (pic rel) and it dims quite well but there is one issue with it, when you power it, it blasts the led strip with full brightness for about half a second, i was thinking in order to fix this i should remove 7805 regulator and replace it with small buck converter so the PWM thing works constantly, my other idea was adding an on-after-delay circuit made from another 555 timer and some BJT at the gate of the mosfet so it turns on only after the PWM circuitry has started working - are those solutions even valid?

Looking for a board house that's cheap.
advanced pcb quoted me 33$ with minimum of 3 boards.

Are there any better priced US based fan houses?

2 layer mostly smd

>>1929872
>I discharged the capacitor and it works now, I think
>discharged the capacitor
>in an AC circuit
what the fuck

>>1929887
>7805 regulator
I don't think that's your problem. Pull the reset line of the NE555 to 5V, that might be the solution you're looking for.

Also your schematic drawing skills could improve a little, it's common to arrange the V+ and V- nodes as straight rails above and below the circuit (if not having the power supply components by themselves in a corner with labels connecting to the parts), with the components showing a progression of the signal from left to right, with as few bends in the wires as possible. I understand that that's the kind of circuit diagram you'd get by reverse engineering something or designing it on the fly, but nonetheless it's good practice to redo it in an orderly fashion.

>>1929872
That does not make a lot of sense but >>1929877
this probably does. Anyhow, glad you solved it anon. enjoy your vaccums

>>1929894
thanks for general insights, i've pulled the reset pin to 5V with 1k resistor but the circuit still behaves the same - even when pot is turned all the way down to low, the led strip flashes and immediately goes blank

>>1929894
I'm pretty new to electronics and electrical things in general. I know that the alternating current from the outlet should be going back and forth in that capacitor, but I thought maybe it wasn't because it was already charged or some shit. I literally bought this motor for its raw material weight from a recycle center with the intention of teaching myself how to repair these kinds of things and to use in a project.

>>1928442
>>1928470
Got some good readings now that I know what I'm doing.

Seems the motor isn't getting any voltage. Not sure why it wouldn't given the other areas are all fairly active.

>>1930045
This one shows the pulse driver getting a lot of nothing, tried messing with the dip switch on the motor driver but the voltage was only slightly raised to ~90mV. Perhaps D13 is the wrong arduino pin to run code from? Haven't run code from one automatically before but it seems like this would be a fair setup.

>>1930045

as you've been told before, you should disconnect the ENA pins coz they've actually a DISABLE pin. 0V or open = enabled, +5V = disabled. real fucking smart naming the thing backwards!

and you cant be changing direction 12000 times a second, coz that's insane, so disconnect those DIR pins also.


>>1930047

ditto on the ENA pins, disconnect them. also, it's odd you're measuring 3.3V on the 5V output. either you've wired it to the 3.3V output, your 5V supply is too weak. measure voltage coming into aduino.

Anonymous 10/14/20(Wed)19:36:44 No.1930060▶

>>1930045

as you've been told before, you should disconnect the ENA pins coz they've actually a DISABLE pin. 0V or open = enabled, +5V = disabled. real fucking smart naming the thing backwards!

and you cant be changing direction 12000 times a second, coz that's insane, so disconnect those DIR pins also.


>>1930047

ditto on the ENA pins, disconnect them. also, it's odd you're measuring 3.3V on the 5V output. either you've wired it to the 3.3V output, or your 5V supply is too weak. measure voltage coming into aduino. if the transformer is weak, you arduino is not gonna go.

>>1928398
panel switches are comfy

>>1930047
Are those differential inputs, or is the -ve one just a local ground? And try the other guy’s advice too.

I have a bunch of analog oscilloscopes but no good DSO.
I need a good storage scope and I really don't want to buy a Rigol. I know the bang-for-buck is great, but I hate the clunky interface so much. I want a scope I can actually enjoy using.
I used Agilent 54600-series scopes in school and they were so smooth, you could tell there was a lot of care and effort put into the interface design.
Since then I've used Rigol and (very low-end) Tektronix digital scopes, and the user experience makes me want to tear my skin off.
Besides the 54600 series, what other scopes should I look at that have that fine smoothness to them?

>>1930125
I have the 54645D which is pretty nice. Has a 16ch logic analyzer built in but you need the cable. Can get it on ebay. There's an extended functions module that lets it do differentiation, integration, and FFT but that's an optional extra. Mine came with it though.

>>1930139
I had my eye on a 54622D. those 16 digital channels are really attractive.
>USB triggering
i'm drooling. (Not on high-speed mode but even still)
I haven't read enough yet to really compare the 54622D and 54645D.

>>1930005
Even if it's charged to the maximum 170VDC (√2*120V), that will discharge into the wall socket (causing a small current spike) as soon as it's plugged in, no biggie. Basically every mains device that cares about noise will capacitors across the mains directly, and they're engineered to be able to handle a sudden current spike when they're turned on. The opposite being a discharged capacitor being plugged across a mains outlet when the voltage happens to be near a peak.

>>1930139
>extended functions module
As in a piece of hardware that you plug into it? Or software?
Personally I just export the data from my CRT scope and do math on it on my computer. Not nearly as fast or convenient, but hey the scope was free.

>>1930148
What would you do with USB triggering? IIRC USB uses buffers on either end and it's used by operating systems so it wouldn't be exactly real-time regardless. If I needed to do USB triggering I'd just get a bluepill or whatever to send a trigger signal for me.

If i have a circuit powered from a battery and i want it to be able to turn itself off, like for example a multimeter turns itself off if you don't use it for a while, what is the easiest way to do this?
I don't want to use something mechanical like a really, but rather something simpler like a fet or some shit, and want to use the smallest amount of components possible

Is this outdoor wiring up to code?

>>1930200
A MOSFET to Bat- should work, with a resistor on the gate to ground. Have the circuit constantly pull the MOSFET's gate up to 5V unless a shutdown command is issued. You'd also need a way of turning it on again, like a button that pulls the MOSFET up (with a resistor so you don't feed Vcc directly into a digital output). Another transistor instead of a button will also work (BJT should be fine unless you absolutely need that 0.7V Vce to turn the FET on), course you'd need something other than the circuit to turn the transistor on momentarily.

>>1930228
i already tried pretty much exactly that but had troubles with current leakage, i even had the pull down resistor on the gate and everything, but it was still leaking current at around like <1ma so the battery slowly drained

>>1930230
Well I guess if you're using a circuit to turn the MOSFET on, and then you remove that circuit's GND connection, the whole thing will float up to Vcc and make leakage more likely. If the output of the circuit that's powering the FET's gate is CMOS, then you shouldn't have such an issue, probably. The harder you pull the gate to GND, the better your circuit should work. Having bypass capacitors after the FET will naturally cause some issues.

>>1927952
>I never thought of loading a sound clip and constantly warping it though

What else were you thinking?

>>1927935
I'm genuinely dumbfounded at this.

How were you intending to do this?

From fundamentals:
You need something to modulate a signal such that the output is the timbre you want. The input can be anything, the principle of modulation can be anything.

I would suggest decomposing the sound you want to make into its frequency components and deciding how you're going to introduce those frequency components.

The easiest way to make any sound is to recreate the instrument that produced the overtones organically.

The easy way:
Record the sound you want to create at each RPM and massage it so that the output clips are smooth in their repetitions and the intervals between RPM in sound clips is small. Save sound clips onto SD card and have a microcontroller read them out based on an RPM value, play the associated sound clip.

>>1928303
Your leads are long and may be low quality. I wouldn't expect the leads to be above 1ohm (max) but sometimes problems of this kind can occur and your leads can be hundreds of ohms.

This would make the voltage divider never reach zero.

Or your voltage divider for the pot is the wrong way around.

Or the reference voltage isn't same as ground.

I want to repair a TV which is arcing. Pretty sure it's the flyback but I have bad eyesight so ideally would like to know exactly where. How can I safely observe this? Just a case of standing back and having the mains close so I can unplug? Should I use anything like an isolation transformer?
Can I just coat it with Corona dope and call it a day?

>>1929891
get it from JLCPCB or some other chinese maker ..their boards are immaculate, cost less,will most likely be made and arrive earlier , and you can order the boards with SMD soldering services or at least getting a stencil

>>1930199
>What would you do with USB triggering?
Probably less than I'd do with I2C and pattern triggering, but I just did a project that involved looking at different types of electrical failures on USB cables, so I've got that on my mind.

>>1927456
I'm trying to make a signal generator based around an IC.

The IC in question (MAX038) has 2 variables to control frequency: current on one pin, and capacitance on another.

What's the best way to vary capacitance? Should I use a varicap or switch in different capacitors with switches?

Is it even worth varying capacitance or would i be better using a fixed value?

>>1930352
>MAX038
No idea about that IC but when I needed a PWM thingie with adjustable frequency (the pajeet shit you find on the web is a crap circuit using the 555 that also changes frequency too when you adjust the duty cycle) I just changed the current on the mirrors that fed the capacitor. Variably capacitance as a hobbist is a pain in the ass to do over a large range.

>>1930063
>real fucking smart naming the thing backwards!
wow , yeah tell me about it. I'll fiddle with some things in a bit and see what I can do. Thanks though!
Also how should I measure the voltage coming in through the arduino's DC Barrel plug? Could be weak because I had it on a power strip with some other things plugged in. I'll try on a dedicated outlet.
>>1930078
not sure what you mean by -ve but I'm just gonna try what he suggested yeah

>>1930352
where do yo usee a variable capacitance in this schematic ? ..you only use potentiometers ...the capacitors are used for varying the wave lenght but you can do that by using bigger or smaller caps ...or using a pot that sets the maximum charge/discharge current which does the same thing...if you want more precise control over a bigger freq range you can make a capacitor range and switch the capacitors with a switch or relay

what's better - having a digital circuit with less levels but more gates, or one with less gates but an extra level?

for example: ax+bx+ab VS x(a+b)+ab

>>1930392
They have this chart which shows for current on one pin, the frequency that comes out on another.

If you vary Cf, you can achieve 0.1Hz to 20MHz, but I'm not sure how realistic varying the capacitance is. Varicaps seem to have a high tolerance, and digital capacitors seem like a pain to work with as a hobbyist.

so I want to make my own heated gloves, any ideas on how to regulate the power on a 12v battery ?

>>1930361
>Also how should I measure the voltage coming in through the arduino's DC Barrel plug?

i stay away from these satan-inspired filthy things, but googling the pinouts should tell you that info.
for example, on the Uno, you can read the incoming voltage at the back of the barrel jack, and the 5V regulated output on the connector.

>>1930444

google ''PWM speed controllers''
add '' schematics'' if you wanna build
add ''ebay'' if you wanna buy

>>1930451
That's all ? A PWM is enough to regulate it ?

Any book recommendations for transformer in-depth design and building?
I have basics and plenty of working stuff but I would like to learn more about specific parameters, like optimizing efficiency or reducing acoustic noise

>>1930444
>>1930459
PWM is standard way to control heating element output. Mosfet, temp sensor and some basic control circuitry and that's it.
Problably possible to do it with 555 as well

>>1930451
>>1930476
well i didnt know it would be that simple, thanks guys

What is the best flux? For which situations those flux are the best?

>>1930063
The first of these actually worked! The CNC moves very slowly around, I would say 1 rev/2 minutes or something like that. The wiring sketch is attached (PUL goes to 23V when the switch is turned on, of course) when you power it but I'm wondering how I can make it spin faster or variably controlled, I think the controller is wrong and the link for what I'm using is below
>https://www.amazon.com/RioRand-7-80V-Motor-Controller-Switch/dp/B071NQ5G71/ref=sr_1_8?keywords=dc+knob+motor+speed+controller&qid=1584394890&s=hi&sr=1-8

Would the dip switches on the motor driver change this speed? I figure it would still be a constant speed but if I could get it to be faster I can make due.

>>1930063
Also meant to say ignore the motor voltages, they function properly at a max voltage of 6V when it's on and running.

Here's the slide table with the arduino, still faults on power and the input to the arduino is indeed 5V. I'm kind of skeptical the wiring from the arduino to the motor driver is right. I also changed the motor wire colors to the 4 listed on top (BLU,R,G,BLA) from the ones on bottom (BLA,G,R,BLU) because I wasn't sure those were correct. It's in the order of B-, B+, A-, A+.
Any thoughts? I'm still playing with it for a few more hours.

>>1930361
>-ve
It's shorthand for "negative". If it's a proper differential line then a "low" signal means pulling the + low and the - high, and a "high" signal means pulling the + high and the - low. By pulling both low you might not be sending a valid signal at all. But I wouldn't know, I haven't read the datasheet.

>>1930434
You're intended to use a single capacitor. Even if you used a variable capacitor (be it a varactor or trimmer cap) you wouldn't get much range out of it (most I've seen is a factor of 10 or so). If you want to have multiple ranges, use an SPDT switch to switch a 10nF or a 3.3µF in parallel with an existing 33pF. Those 3 ranges cover about as much of the total frequency space as you can want.

>>1930500
>The CNC moves very slowly around, I would say 1 rev/2 minutes or something like that
Calculate how many degrees per pulse, and see if it lines up with the number expected from a stepper with that many poles. If you want it to go faster, send it pulses faster.

>>1930492
At this moment my favorite is Chipquik SMD291.
Works well on all solder types, not too corrosive, tacky enough to hold components down but not too tacky for non-tack applications.

>>1930430
what is better is a subjective question

better relative to what ..power usage , cost, size , complexity etc

>>1930434
you are supposed to use one capacitor and vary the input current with a variable resistor...usually frequency generation is done for a predetermined range ...as i said in the first place you can put in multiple capacitors and switcvh between them with a relay or multiple throw switches

>>1930459
PWM means pulse width modulation and is measured in amplitude and duty cycle

it basically turns a swith on and off for a predetermined ammount of time ()the duty cycle)

so if you have a 50% duty cycle it means that the switch is turned on for half of the time which means you will use half of the maximum power

if you have 20% duty cycle it means you will have the switch turned on for 20% of the time and that means 20% of maxumum power available

the point of this is easy power regulation with very little power losses due to overheating elements in the controller circuit but you will have pulses in the voltage and current to the load but in usage in heating for instance , the load has a bigger inertia than the pulses have ability to skew the output result (heat)

for instance a normal wolfram fillament bulb takes a while tu cool down and therefore turn off where for instance a LED turns off instantly as soon you take away the power ...so if you pwm a LED it will flicker (depending on the frequency) but a fillament bulb will just be dimmer with not noticable flickering

>>1930555
>a LED turns off instantly as soon you take away the power
>if you pwm a LED it will flicker
A sufficiently-sized LC filter can remove that flicker in exchange for some expense and bulk. Basically turning it into an unregulated buck converter. Adding regulation is possible, but not really necessary for such a load.
Some LED phosphor mixes may display slightly different colors when underdriven though (less blue IIRC), when compared to being fully driven at a partial duty-cycle for equivalent average luminosity.

>>1930517
Ran it on 400 pulses/rev since that's the fastest setting. One rev every 110 seconds so that's a bit less than 4 pulses/second. If it's 400 pulses for 1 rev then each pulse is 1.11 degrees. How can I send more pulses/second directly without tampering with other factors?
Also, perhaps related, I am unsure what changing the current does. I ran it again at full current but speed is unaffected, seems like it just draws more power.

>>1930430

gates cost money. as much as 4 centavos, so your boss will fire you if you use more than the minimum. however, levels are free.

>>1930500
>>1930503
wait im confused ..the link you sent is a DC PWM motor controller that has input (fixed DC value) and output only ...but what yo uare drawing is assuimg a stepper motor controler?

which driver do you have then in the end ..the thing in the amazon link is not gonna be driven with an arduino its a stand alone controller and its not for steppers

what exactly are you using to drive the motor ..
send a picture of the motor with the cables in view and prefferably the nameplate and take a pictuer of the motor controller with the outputs/inputs in clear view and prefferably a namplate or write in the name in your post

also give a clear picture of the dip switches you have been mentioning

i think there are multiple things swapped around in this thing

>>1930560
>I am unsure what changing the current does

you're supposed to match it with the current that the motor is rated for.

>>1930558
i knwo all that but i was talking about the general idea behind pwm for the new guy to understand i was not going into filtering or such stuff since its kinda unnescesary for heating purposes anyways

Rate my lipo charger.
It also relies on binning diodes.

>>1930562
They're 2 different systems. See pic.
The left corresponds to >>1930500, the right corresponds to >>1930503.
The dip switches are just small switches on one panel that control pulse/rev and current. On the picture here >>1930560 I ran the 400 pulse/rev option since it's the fastest.
>>1930563
Ahh alright. Thank you.

>>1930560
>a bit less than 4 pulses/second
Then, send more than that? Why are you only sending 4 pulses per second?

>>1930567
>

>>1930570
pic rel is for the right part with the arduino

your left side is wrong from the begginiing
you dont use stepper motors for chuck motors ...you use a normal DC motor because you dont want those vibrations in the rotational part that should be as stable as possible , also stepper motors have very low torque at speed

second thing with the left side is that you put on a PWM controller to the input side of a stepper controller that is supposed to recieve fixed and stable impulses...the thing you connected is a pwm motor driver for DC motors which means it will most likely be filtered or have impulses in a duty cycle instead of frequency

left side should either be changed to a normal DC motor or you will need to pull out one more digital pin from your arduino and feed it pulses directly to the stepper controller like on the right side

>>1930567
> runs away from you thermally

>>1930579
I do not know how to increase the pulses per second.

>>1930570

i'm assuming it's the one with the PWM speed controller that's running slow. if so, one thing to try is to use the correct resistance on PUL. you're using almost twice the recommended value. now if you put two of those 3.9Ks in parallel, then a 470 ohm in series with that, you get close to 2.4K.

as for the arduino one, the voltage on PUL is really really low, so you're gonna have to find an independent way of knowing if pulses are actually being send. an oscilloscope would be best, but maybe an LED and 470 omh resistor in series might do the job.

>>1930570
>>1930581
the PWM DC motor controller is supposed to be connected like this

so as i said either connect your arduino to the stepper controler liek you did for the right side to the stepper controller

or do the chuck part with a DC motor which i highly recommend

>source: i made a CNC mill for my mechatronics degree

>>1930587
first of all he most likely messed up the motor wiring to the controller ...the second thing is that PWM driver is not supposed to be connected to the input of the stepper controller ...third thing is i want to see his arduino code because i bet thats kinda backwards too

>>1930567
heres your (You)

>>1930592
also i forgot to say that you should probably not control the inpust of the controller directly with the arduino and should use some transistor for switching cause its most likely its pulling too much current and overloading the I/O pins ...

try with adding a 100ohm or 220ohm resistor in series with the arduino pins to the controller

>>1930592
>.the second thing is that PWM driver is not supposed to be connected to the input of the stepper controller

this has been known for a long time. but the dude is dead set on using it that way. for historical reasons. it supposedly worked in the past. his eyes will open at some time, and jesus will fill him with the holy spirit (bourbon).

>>1930597
well it will work partially but it would aslo work partially if you took the wire and did the parkinsons dance on the input.... its not even remotely effective and are probably losing 70% of the impulses

>>1930581
Thanks for the input/background, it helps a lot. Yeah the goal was to have variable frequency controller so the CNC would operate...as a standard CNC does. What sort of controller would be a suitable substitute? All I see for a knob controller is stuff like that amazon link and similar rates stuff that are PWM unless I'm missing something.
>https://www.amazon.com/s?k=brushless+motor+knob+controller&ref=nb_sb_noss

Going to try that diagram shortly.

>>1930596
>adding a 100ohm or 220ohm resistor in series

naw, dude, all the inputs are TTL-compatible: 240ohms in series with opto-isolator LED.

>>1929891
I've been using Aisler, it's a german company but if you order from the US site they get fabbed in the US. Pricing formula is not obvious but it comes out to about $15 for 3 ~2sqin boards and significant discounts when you buy like 15-20. The website shows estimates in euros but they've been charging me that number of dollars so I think it's a rendering glitch.

>>1930600
idk if you are not able to read or have selective memory ..the motor on the chuck part (left ppart of your picture) is not suitable for what you want to use it for ...get another motor : a normal DC non stepper motor

nothing is wrong with the PWM driver it looks fine you just need the motor its used for it and it will be variable speed (the potentiometer knob)

you need pic rel that has two wires and has a linear and fixed power band (the stepper motor you want to use is slow , has a bad power band for high speed and has vibrations)

the motors for the linear rails are fine and are nescessary to be stepper motors so the hthing you have connected to the arduino will be fine if you dont mess up the wiring (the right part of your picture) (or DC servo motors but those are complicated to use)

>>1930584
what's sending those pulses?

>>1930199
>As in a piece of hardware that you plug into it? Or software?
No, it's an actual hardware module. It attaches in the back. HP 54657A or 54659B. Former is the GPIB measurement and storage module, latter is RS-232 and parallel. Both give you the extra functions. I think I have the 54569B but I'm not sure off hand.

>>1930625
his own hubris

>>1930589
That's fair. Can understand that better now.
>>1930592
I just fixed the motor wiring after consulting a better source. The arduino code isn't mine. The second part of that is fair, I am unaware what I am doing.
>>1930597
I am not dead set on using it that way, I just don't really know what I'm doing.
>>1930616
That's fair. I think I can do that somewhat easily now that you explain it's the actual motor's fault. I also apologize as I have a problem with understanding electrical terminology. If I just swapped out the motor and dumbed it down it'd be a solid normal setup.
>>1930625
I believe the knob controller is what's sending the pulses but the knob controller is acting as an additional on/off switch.

I have been interested in electricity for some time.
How do I get licensed to buy electronic components? Do I have to call up the State department and submit a background check before I am cleared to buy resistors and a power supply? I heard only a licensed electrician can own a mutlimeter and has to renew ownership license ever 2 years which costs 200.

>>1930638
what ?
in the first post there is a collection of electrical component resellers...yo go there choose what you want and order it...the same for electrical equipment like multimeters and everything else

you most likely need an electricians license to be legally allowed to do in house or industrial wiring professionally whic most likely requers a degree or some kind of school certificate or other qualification

but to use and buy equipment and parts is not illegal and does not require any kind of licences ...who told you that ?

>>1930642
Common sense told us that, you would just start sriving a car with out a license would you?

>>1930636
you are basically on the right track of getting it to work ..i would recommend you get someone that knows how to do electronics closer to where you live because you are pretty much almost there with making it work but it requires tweaking and setting up things and checking if its all connected properly

i could make a list of things to do/buy/check and check the arduino code ..but honestly i cant be assed and dont want to take up the time since doing all this over the net is tedious and finnicky

literally the best thing to do right now is to not touch it anymore and get someone who is familiar with wwhat you are doing to give you a hand ..you got to the part where it would not take long and its built enough for people to not care about making you pay them and/or would most likely be helpful enoug hto give you a hand


troubleshooting online with a person that does not know what he is doing is a beautiful recipe for disaster/breakage /electrocution

>>1930645
>>1930638
oh another troll ...at least he didnt mention arduinos yet

>>1930567
A for effort
F for fire

>>1930645
I drove a car without a license

You dont need a license to learn how to drive a car..you need it to drive a car legally on the roads

>>1930638
>I heard only a licensed electrician can own a multimeter

Oi you got a loicense for that m8

The probes can be quite sharp not gonna lie

>>1930658
A friend of mine didn't put the cap back on his probe and then looked straight onto it and the electrons jumped off it and he got his eye infected.

Anytime I handle electricity I am sure to wash my hands to the tune of mary had a little lamb. Also you have to use egg white to neturalize an electrical burn to stop the chain reaction

>>1930638
>I heard only a licensed electrician can own a mutlimeter
Owning a multimeter is extremely dangerous.
Before you know it, you'll own two multimeters, then four, then so many you don't know what to do with them all.

>>1930638
Your very wise for asking, I had a friend who disnt knownwhat he was doing and thought he could just buy resistors and hook them up. Well he got 220 nano farad resistor and it causes so much interference with his wife's menstrual cycles that she had to be hospitalized for indigestion. He also got some lung infection for not cleaning the resistor with tallow before plugging it in. Because of this he's disabled now had to amputate his pinky toes because ot it, dangerous shit!

>>1930676
A kid I knew became so obessed with mutlimeters that he qould whore himself out at subway stations to keep hia mutlimeter habit going. It wasnt even it's usuage it was that new plastic smell he was hooked on.

He would open the packaging then put it all in a plastic bag and juat huff it all day.

>>1930638
Lol you got me gigglin

>>1930636
Is that "knob controller" meant for use with stepper motors? Because it looks like a simple DC motor speed controller to me. You need something to send it short pulses at a variety of frequencies, your little box with a knob on it obviously isn't doing that, so revise your circuit. Just use an arduino for that instead, or a 555 timer or comparator/op-amp oscillator with an adjustment pot.
Might as well make a post on the woodworking general asking how to turn a table leg with a table saw instead of a lathe.

>>1930647
Yeah I know what you're getting at. I can get the chuck going pretty easily imo. Not worried about that after talking today.

As for the slide table I tried the most recent thing you posted + the resistors, still a crapshow and both PUL/DIR are around 75-85mV. Not much changed from the last steps but hey it was worth a shot.

Tell you the truth I'm a lot closer to electronics savvy people than I'd like to admit and I could easily ask for help. I'll try it tomorrow. Really just want this shit to work. Can understand you not wanting to go through the code. That'll be the next step before this fault gets fixed. We'll see if I can get it done tomorrow.

If only there was some way to unfollow or block accounts on this website.

>>1930683
I started on multimeters real young. they say it's not a gateway drug but by the time I was 14 I was hooked on oscilloscopes, trolling for hook-up wire on craigslist, sticking my probes into all kinds of seedy boards.

>>1930735
>some way to unfollow or block accounts

click Settings at the bottom of the page and check "'I hate fun''.

>>1930735
you need a 4chan Gold Account for that.

>>1930582
>>1930653
Fun fact: I left charging some chinkshit 18650 from hoverboard battery for a week, no fire.
>>1930593
thanks
>>1930638
>he doesn't own multimiter illegally

>>1930735
Can probably get 90% of a person's posts with clever filtering. Not that I'd put in the effort, unless you already have some program that lets you flag posts similar to the ones that you want filtered in order for it to optimise the filtration parameters.

>tfw stable grid power
I honestly wish I had unreliable power so I had a good reason to come up with better backup power systems
I love powering shit with big batteries

Question about inverters. If you power a purely reactive load, does any appreciable current need to flow into the inverter? I see UPSs are rated by VA not by W, so do they not handle high power factors efficiently? Where would that energy all go if not into the load?

Wait, if I have a logic power supply of 5V and comparators and such running on 12V, I’ll need to clamp those comparator outputs to 5V in order not to fry the logic IC. But if the 5V rail is made by a 7805 running on that 12V rail, which can’t sink current, then using a diode and resistor won’t work to clamp it at all.
How would you solve this?

>>1930956
circuit diagram

>>1930555
Can I use a PWM at any frequency ? Like 1Hz ? I could use an astable 555 + mosfet (like >>1930476 said) to drive the 12V/3A for example ? I don't really need a temp sensor

>>1930961
I’m on mobile so I can’t until I get back home. I just want the easiest way to shift a 0-12V signal to 0-5V, which doesn’t require sinking current into the 5V rail.

I’ll draw a diagram later.
I may need to do “-9V - 9V” to “-2.5V - 2.5V” later, so something using a MOSFET might not be as simple as with the common GND. Best I can think of is a zener or TL431, but I wonder how fast either would be.

>>1930978
>But if the 5V rail is made by a 7805 running on that 12V rail, which can’t sink current, then using a diode and resistor won’t work to clamp it at all.
Ok. But what you said does not make a drop of sense. I think you would understand it once you drew the circuit

>>1930969
Yes, sure. But you might notice a little periodicity in it, so I’d use at least 5 or 10 Hz. Not having temperature control is just fine if your heater will never get too hot without it, but 3A is a fair amount, so a small bit of drift in some components might lead to significant heating. Probably fine but do the first tests with a thermometer, not your fleshy appendages.

>>1930961
>>1930979
this

>>1930996
Also this, showing the 7805 needing to sink current, which it can't.

>>1930999
And this potential solution, that looks kinda shitty

>>1931000
Note that this is a solution for the second part of the question (-9V to +9V). A single zener would work for the first (0V to +12V), but the question as to its efficacy remains.

>>1931000
what is the problem of using a zener to ground or a transistor as a level shifter? or even a resistor divider

>>1931002
I want the rising and falling edges to be fast, and was wondering if a zener would give me problems with that.
I'm trying to think of a reason why a resistive divider won't work, and the best I can think of is "the pullup resistor of the comparator output will interfere with it somewhat". There is some leeway with CMOS logic levels such that I could probably do it just fine with a 10k pullup and ~100k dividers, I guess? I don't think my shitty 10% resistors will be an issue here.

sorry for being an idiot

>>1931002
>>1931001
https://www.falstad.com/circuit/circuitjs.html?ctz=CQAgjCAMB0l3BWcMBMcUHYMGZIA4UA2ATmIxAUgpABZsAoAJXBppGMPE46l5qqRUh0BExZsU-LiElCZtKmBThlw0QCdxMqSjx5tc7Lkj0ALjL0GQ2BMtm8IAWhrRSbtxkIk316CnfuCBh4HJ4Apo5ginD0AO7WtjIInDbK2GhQ9ADmCWkZqbmZmgUokoU80fBxWjwFFdUlZfxUpWwmAPIKLU2EEmVC9AD27CC9fJDE+oLQEIr0QA
>>1931003
it is not stupid it is just that you did not provide parameter or even a schematic so anything can work. when you narrow things down you can get into specifics. You could try the resistive divider and if doesn't work as you expect do a more complicated shifter. Also "fast" can mean a lot of values.

>>1931004
>failstad etc.
Yeah a transistor inverter is probably the best active solution for common-ground reduction, the inversion itself almost certainly isn't an issue.
>Also "fast" can mean a lot of values
Fast for audio levels. If my maximum fundamental frequency is 5kHz or so, then I want an edge significantly faster than that, say rising in 1/(40*5kHz) = 5µs. At 18V pk-pk that's about 500ns/V. Heck, don't even know if my shitty comparators can go that fast. 10 times slower would be bearable I guess, but no slower than 5µs/V. Resistors are a good choice at getting this fast, though a schottky transistor solution with that extra capacitor thing might actively improve upon the comparator's slew rate, provided I can get that to both rails.

>>1930911
reacitve loads still pull current it just isnt useful since it does no work

>>1931008
>audio
lmao, just do the resistors

>>1930969
>Can I use a PWM at any frequency
yes theoretically but under a certain frequency it stops being useful ...the higher the frequency the higher the efficiency and you can filter it easier

>>1930956
>>1930978
tweak the passives for 12V instead of 10V

>>1930956
Are your comparator outputs push-pull? A lot of comparators have open drain outputs, in which case you just put your pullup to 5v instead of 12v.

>>1930956
>>1930978
voltage divider after comparator output and add voltage follower afterwards

>>1927456
Bachelors degree in electrical and electronics engineering here.
Ask me anything, though my degree is worthless, so I probably wont know

>>1931044
>though my degree is worthless
I often feel that way too.
Do you think you didn't get enough hands-on experience? that's one thing that frustrated me, they seemed to think that lab work and actually building circuits was an afterthought. Even when I had lab classes, building your circuit was often optional. You could just get credit for showing the simulation.
Like, we studied Fourier series, but never learned to use a spectrum analyzer, I had to teach myself that. Got taught about components and how to model them, but never learned to read a datasheet.
When senior project time came around, students who hadn't spent time doing their own hobby projects outside of class were pretty much dead in the water. I had to help people learn basic stuff like using a breadboard, that we should have learned in first year.
It was an embarrassment, I thought.

>>1931078
>When senior project time came around, students who hadn't spent time doing their own hobby projects outside of class were pretty much dead in the water.
holy based is it really that bad?
I've been doing this shit since I was 17 and I thought everyone else was going to be leagues, leaps, and bounds above me in skill once I got to Uni

>get $50 amazon gift card from work
I'm so, so sorely tempted

I have a question. Why do chargers like pic related have a sticker informing both their output voltage and output current? Shouldn't this information depend on what i'm using it for? If i try to use it power something with less resistance than what it is intended for i should get a higher current, right?

>>1931085
>I've been doing this shit since I was 17 and I thought everyone else was going to be leagues, leaps, and bounds above me in skill once I got to Uni
So did I!
My freshman year, I brought an old tube amp into the lab to rebuild it. The older professors were amused, they said, "oh wow, you're a hobbyist! That's rare". When they reacted like that, I got a bad feeling that things weren't going to be the way I expected them to be.
Over the years I met a few students who really liked electronics, had been doing it on their own for a while, and put effort into doing their own fun projects and learning stuff for themselves. But just a few.

I think a lot of students go into engineering because they were academically gifted in high school, not because they had any kind of passion for the craft. The courses were taught accordingly. Sucked for me, because I was academically retarded but just had a knack for all things electrical and mechanical.

Being out of school and in the industry for a while really made me realize that the most important parts of engineering education are the parts that the school(s) overlooked. People who come here fresh out of school are often seriously lacking in fundamentals even though they did very well academically.

>>1931091
>If i try to use it power something with less resistance than what it is intended for i should get a higher current, right?
That's right, and when you do that, the supply will shut down (and/or the voltage will droop) because it can't supply that much.
They're rated for constant voltage, and maximum allowable current.

>>1931093
So if i use it to power something with a higher resistance than intended i would get the whole voltage and current they're capable of?
Also what makes them shutdown?

>>1931095
You would get the whole voltage.
Most USB adapters, for example, are rated for 5 volts and 2 amps. If you put a 5-ohm load on it, you will measure a voltage of 5 volts (or slightly under) and a current of 1 amp, and the supply will run just fine.
These usually have a type of circuit called a "flyback converter", which is controlled by a chip. That chip will shut it down for overcurrent, overtemperature, etc.

>>1931096
If i put a 2.5 ohm load on it would i get the 5 volts and 2 amps?
I know they basically have a transformer and a rectifier, would those components on their own be able to provide their maximum output without problems if it wasn't for that chip assuming they don't overheat? The output of the transformer doesn't depend on the load, right? Just the number of windings, right?

>>1931091
because you need the maximum voltage and current to know how much power it can give out...also that the maximum rated current , i have a lot of friends asking if they can charge a phone (1A charger for instance ) with a tablet charger (2A) and will that blow it up ...basically no because if you phone sinks only 1A of current then the charger will work at 1A since those are constant voltage sources

if you load them with something that requires more than the rated current then it will just not work (or if its a lamp for instance it will not glow with the maximum brightness)

>>1931091
Majority of power supplies are constant voltage power supplies because for most practical uses it's the most useful. So they will try to maintain their rated output voltage, usually is a bit higher with no-load connected and drops with increasing output current (until hits current limit)

>If i try to use it power something with less resistance than what it is intended for i should get a higher current, right?
Completely wrong. Resistance determines how much current can pass through it depending on voltage. So that's why most appliances also say what type of input voltage and how much current they need.

If you try to power 12V 10A appliance with 12V 2A power supply, your appliance won't work or work like absolute shit
If you try to power 5V 1A appliance with 12V 2A power supply, you will kill your appliance.
If you try to power 12V 1A appliance with 5V 10A power supply, appliance won't work.

>>1931044
>>1931078
my dad is an electrical engineer by trade (he has no uni degree because life circumstances didnt allow him to get it) and has been making electrical devices and fixing them for over 35 years and i grew up close to that ...i didnt really give myself into it as i should and i regret it nowadays but i did end up getting a bachelors degree and am working on my masters , also i work alongside my father

i always thought i was very low level in the knowledge department but holy shit sometimes i feel like most of the professors are bullshit hack that never held a soldering iron in their hand...90% of my colleagues literally never saw or held an electronic component in their hand and could not point out a resistor capacitor inductor diode and transistor with 100% accuracy if their life depended on it


so basically if you have any bit of experience with electronics , let alone if you managed to do some projects by yourself you are most likely already a better engineer than most of your peers (they might have more theoretical knowledge and might still be much better scientists than you...and i have that situation , but sometimes there are professors that ask me to come help them set up some test gear or device because they dont know how they woould do it , but the theoretical work they do is astonishing)

>>1931100
It's a lot more than just a transformer.
A flyback converter rectifies the incoming AC to DC, then switches it really fast (100s of KHz) to drive a smaller, more efficient transformer. The output is rectified, filtered, and there's some feedback to regulate the voltage.
The output power rating depends on the transformer, the switching transistor (often built into the control chip), and the rectifier.
tl;dr: You can't really push it harder than what it's been designed for.

>>1931090
>50W max

thats 5W real power if you mean to use it for anything serious fyi
all the testing we did shows that effective power in power applications that require uninterupted power for solar cells is 10% of rated power (in a place with regular climatic changes and no solar power tracking so results may differ for places like constant sun states , and using sun followers..... this is practical use tested)

>t. i do solar charging for roadwork signs

>>1931100
transformer and diode bridge rectifiers in the common use you see in books has not been used in quite some time

>>1931106
I have some competent teachers but a lot of shitty ones. The shitty ones are usually there by a process of "academic incest" as we call it.
>graduate -> masters in europe -> Phd at home or europe -> teaching
WIthout any actual professional experience in the middle. It really shows sometimes, but this is brazil. No idea about your area. I am still graduating so my opinion is worthless. I had class mates who still had the "cram school" mentality of learning for the sake of tests and forgetting everything afterwards even in important classes such as circuits 101, signals and systems and control.

>>1931113
>high latitude solarlets
lmao

>>1931123
i work in the mediterranean ..we have high insolation but its not the desert and its close to the sea so we have a fair ammount of rain

>>1931125
Oh good. I was in uppsala the other week and I honestly have no idea why the swedes think it is a good idea to put solar power in sweden in the scale they are doing.

>>1931122
most of teachers are usually people that finished university and stayed for their PhD and basically only were in academia ..so it makes sense to continue to do that and they become teachers , some go and work or open their own companies but most are just good scientists and nothing more

where im from in high school you can go and continue general education which is basically just more regular school, or you can go to a trade school
i finised electronics based trade school as a mechatronics technician and my graduation project was a CNC mill (my colleague made the physical thing and i did electronics like motor controllers and interfacing with linuxCNC) ...when my professors find about that they are all surprised, also all the lab work we did i already finished in high school , but im a bad student and have shitty grades but i have a better engineering brain so i stick to application electronics , and they stick to theoretical so its basically a win win lol