We found this circuit that triggers an SCR in the Encyclopedia of Electronic Circuits volume 5 of 1995. The circuit is powered by voltage according to the warning load.
We found this circuit in an English magazine in 1975, but it can be easily assembled, as the...
Found in a 90s Popular Electronics, this circuit uses a 741 to generate frequencies from 0.1 to 30...
This circuit is from an 80's documentation. The circuit makes use of a component of the era, the...