Response of relay amplifiers with feedback

THE RELAY AMPLIFIER with feedback is a simple and economical solution to many power amplification problems. The configuration of the primitive relay amplifier is shown in Fig. 1. The relay is assumed to have both deadband and hysteresis as shown. Inasmuch as the low-pass filter is the only predominant lag in the feedback, it might be surmised that the relay amplifier is stable under normal conditions and indeed this may be shown.