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PinkDuck, to askelectronics in What's a simplest way to get -5v from +/-12v?
@PinkDuck@kbin.social avatar
  1. it does nothing 😅 I just forgot to remove it from the sim
  2. you mean like power it with 0+5v? I think it won't work with negative input voltages then, right? and I'm using tl074 and I'm not sure that 0+5v is enough juice for it, and I use remaining 3 opamps for other stuff, so it's not really an option for me. the sim didn't have shottky diodes, so this measurements are not 100% accurate, but I used this approach to protect arduino inputs in another project, and it worked well. And yeah, I cranked up the input signal to +/-10v just to check the clipping, it'll normally stay within +/-5v

I already ordered PCB for the prototype. I hope it'll work fine. Thanks a lot for your help :)

PinkDuck, to askelectronics in Electronics for toddlers?
@PinkDuck@kbin.social avatar

maybe something like littlebits kit? I haven't tried them myself, but they look fun, educational and kids friendly (not sure about 3yo thou)
https://www.youtube.com/watch?v=E7B0mWvnE1Q

PinkDuck, to askelectronics in What's a simplest way to get -5v from +/-12v?
@PinkDuck@kbin.social avatar

No, with 0 Ohm I get a perfect 0+5v sine, just as I need. It's the other way round, it'll amplify the signal and clip off the top at about + supply voltage when you increase the resistance in the feedback loop, but it's not exactly square wave, as the bottom part of sine will remain intact. I use clipping schottky diodes to protect the arduino from voltage outside 0+5v range, this way if you increase input signal to say 20v peak to peak, you'll get more square-ish wave in 0+5v (I've attached the schematics)

PinkDuck, to askelectronics in What's a simplest way to get -5v from +/-12v?
@PinkDuck@kbin.social avatar

ah, a little bit of thinking helped me realize that I don't need 1k in inverting loop and then I'll get 5v instead of 5.05v :) and 100k can also be replaced by 1k

PinkDuck, to askelectronics in What's a simplest way to get -5v from +/-12v?
@PinkDuck@kbin.social avatar

it worked! (at least in the sim)
thanks a lot!
I'm not sure I got all the math right, since I get 0 - 5.05V on the output, but it's not a deal breaker for me.
I attached the schematics, but not sure that images in comments federate from kbin to lemmy, so if you don't see it, try opening an original link to this comment.

PinkDuck, to askelectronics in What's a simplest way to get -5v from +/-12v?
@PinkDuck@kbin.social avatar

thanks! gonna give it a try tomorrow. I'm pretty new to this, and never used opAmps in non-inverting configuration, so I missed this option

PinkDuck, to askelectronics in What's a simplest way to get -5v from +/-12v?
@PinkDuck@kbin.social avatar

Oops, the schematics didn't attach for some reason, let's try to add it here

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