Cursed circuits #6: reverse avalanche oscillator (lcamtuf.substack.com)

This isn't particularly cursed. I mean we've had avalanche pulse generators for well over half a century easily. It's just exploiting semiconductor characteristics they don't teach you in the usual garbage undergrad textbooks.

You can even use it to make a simple audio synth: https://www.lookmumnocomputer.com/simplest-oscillator

Delightfully cursed.

I wonder how consistent the breakdown voltages are between manufacturers? I mean, I am sure there is some spec, but is it not just a minimum in this case?

What would happen if you added a capacitor (to ground) on the base? Could you adjust the frequency?

I would never have thought to try this circuit for fear of letting out the transistor's magic smoke.

> "It’s hard to build an oscillator"

I would beg to differ. It's hard to not build an oscillator. An awful lot of digital design is avoiding building oscillators all over the place.

Incidentally, the coolest anti-oscillator I've seen used the back EMF from a relay to push a transistor past its breakdown voltage, and that was the oscillating element.