We found this circuit in the 1983 Radio Electronics Special projects magazine. The components are common, and the circuit drives a relay. The power supply must be isolated.
This SCR circuit activates a buzzer when triggered. The circuit is from a Popular Electronics from...
This circuit is used for incandescent lamps and other resistive loads up to 3A using the TIC206. This...
This circuit is from 1995 documentation, but can be easily assembled today, as the components used are...