Level controller switching circuit for carrier frequency system - has pilot level discriminator and delay circuit to inhibit locking of controller by alarm circuit

摘要

The switching arrangement is for a carrier frequency system having a pilot-controlled level controller (PR) which has a setting device, a pilot discriminator and an alarm circuit. After switching on a delay circuit inhibits locking of the controller by an alarm circuit. The controller is regulated to a nominal value in the presence of a pilot signal and the alarm circuit becomes effective after an interval which is determined by a delay circuit. Flip-flops of a binary counter increase the operation of the delay circuit so that. on failure of the pilot, the amplification slightly exceeds the difference between half the operating range and the alarm level.