Differential gain adjusting amplifier system with selectable electroluminescent differential photocell attenuation

摘要

An audio attenuator has a differential signal path with photoconductive cells connected to vary signal levels in the circuit. Electroluminescent light sources adjacent to the photoconductive cells direct light onto the photocells. The electroluminescent light sources receive the input audio signal, an output audio signal, or some other signal. The light sources are connected to a differential control with receives an input of the attenuator circuit. The differential control provides a control input to a differential audio amplifier which receives the input audio signal. The varying signal at the control input effects a variation in the gain of the amplifier. A compression or limiting of the input signal results, depending on which signal is connected to the light sources.