This circuit is an alternative version of the previous one also found in the July 1995 Electronics Now magazine. The triac must be equipped with a heat sink.
In this circuit of a 1968 publication the unijunction may be 2N2646 and the transistor BC548. The...
This circuit was found in a 1969 CQ magazine. It is intended for coupling telephones to radio...
This circuit, which can be used as a shield, was found in Radio Electronics from the 90s. The...