Distortion compensating circuit for nonlinear circuits - has square wave input shaped and used to control analogue relay generating output

摘要

The distortion compensating circuit, particularly useful with voltage controlled diode tuning units, is based upon semi-conductor devices in an integrated form insensitive to temperature and humidity variations. The compensating circuit accepts a digital input in the form of a square wave from the digital control circuit of the timing system. The signal is of constant frequency with variable mark/space ratio dependent upon the stored data in the tuning system. The signal is processed through an analogue relay (12) generating a constant amplitude output with a pulse width equal to the input. An RC filter with a long time constant provides a compensating signal, over an amplifier, for the other analogue switch (18).