SCRs and Triacs

[mgrEIGHT]

i was just wondering if these have any use in stompboxes. I'm pretty sure they're in microwaves but why not fuzzes?

[R.G.]

Both types of thyristors are primarily power switches. They turn on to a voltage of about two diode drops when you drive their gate, and never turn off until the current through them drops to zero. They're used for controlling AC power line stuff where the power turns off 120 times per second, giving you a chance to modulate the next turn on cycle.

While I can concoct situations where you might be able to use them for audio, it's quite difficult to do, and there are simpler means to do them. I suspect that's why you don't see them in effect schematics.

[H S]

I looked at this once - The commercially available SCR's and Triacs are built to work with 120v.  If I remember right and didn't screw it up, they don't trigger at audio signal voltages.

Can you make a device to use with audio signal voltages out of signal transistors?  An SCR is a pnpn device--can you hook up a pnp and an npn (gate to emitter, collector to gate) to make an SCR?