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.
The presented differential amplifier, indicated for instrumentation, was obtained in the 1994...
This circuit provides a signal when dialing occurs. The circuit is powered by the telephone line...
This circuit uses two TTL trigger inverters to generate signals that can be adjusted at R1. The...