CircuitSourcery: Schematics, Manuals, & Modifications

[UnderstandDavid]

Lads, this is an absolute wet dream of a thread. Thanks so much for posting all of this, there's some absolute gold here!

I'm currently sitting in my studio, surrounded by electronics and tools...let the games begin.

[FAP]

I've been looking for a way to make a 555 IC flash an LED in a sine wave-like pattern; the LED would become a vactrol and eventually the whole circuit would basically be a sine wave LFO.
I wanted to have an alternative to the much easier square wave flashing you get out of 555's, to add some variety and subtlety to the patterns I could make.
Well it took many days of dicking around, but I've finally come up with a working schematic.
I figure this may be of interest to you fine folks:

This circuit was heavily troubleshot & modified from a schematic posted on this long-defunct and unsecured website (click if you dare):
http://www.pcbheaven.com/circuitpages/5 ... lsing_LED/

To get an idea of what it does, you can see the original version of the circuit in action here:


Please note that I don't have an oscilloscope, so I can't confirm if my circuit yields a 'sine' wave in the strictest sense.
What I do know is that you can adjust the fade-in & fade-out of the LED's flashes, essentially creating sawtooth, reverse sawtooth and de-facto sine or possibly triangle waves through various combinations.

TL;DR I figured out a way to make a sine wave-like LFO with a 555 and a vactrol (and some other parts).

[NoiseWiki]

Viewed 1336 times

http://www.chuacircuits.com/

[crochambeau]

Nice! Chua circuits can be fun.

I drafted a PCB a while back after some protoboard builds, but over all I haven't sunk a lot of time into them. They seem to prefer singing in the higher frequencies. Aside from some open ended connectivity (which demands very high impedance loads and floating differential inputs) I pretty much lifted the schematic directly from that site.

Viewed 1333 times

[FAP]

What do you use to draft your PCBs, and who makes them?

[crochambeau]

What do you use to draft your PCBs, and who makes them?

KiCad is the software I use, I recommend it absolutely. That particular PCB is from OSHpark, I have also used JLCPCB (cheaper, but without the feel-good of domestic production).