The integrated circuit used in this circuit is from the time of publication. The circuit is from a Radio Electronics from October 1987. The triac must be equipped with a heat sink.
This circuit was published in a 1979 magazine, but it can still be easily assembled, as the...
This configuration found in GE documentation from the 90s, can also be seen elsewhere in this...
This simple circuit has good gain and can be implemented with any general-purpose transistor. The...