A CIRCUIT FOR CONTROLLING AC/DC POWER LOAD

摘要

A control circuit for controlling a DC current and an AC current through an acoustic transducer such as a ringer or a buzzer in a telephone. The control circuit comprises a current controlled output stage with an output terminal for the acoustic transducer, and a driver transistor of which a main current path drives the output stage. The driver transistor has a single control input for controlling both the DC current and the AC current through the acoustic transducer.