TEMPERATURE INSENSITIVE DC VOLTAGE DETECTION AND PROTECTION CIRCUIT

摘要

A circuit for detecting a DC signal in the output of an audio amplifier and for uncoupling a speaker in response thereto comprises a low pass filter whose output is coupled to one input of differential amplifiers whose other inputs are unbalanced by respective positive and negative threshold biasing potentials. The differential amplifiers are directly connected to respective current mirror circuits, and their high impedance side collector outputs are applied to the inputs of an OR circuit whose output in turn controls the speaker uncoupling.