Found in a 1960s RCA documentation, this circuit applies to most common triacs. The trigger device is a neon lamp and the sensor is an LDR. R is typically 100k and C is 220 nF.
Found in ancient documentation, this circuit uses a high voltage transistor of the time. Observe...
This voltage inverter uses a small transformer. The circuit was found in the April 1995 issue of...
We found this circuit for musical instruments in the March 1992 Radio Electronics magazine. The...