Pilot control circuit for data transmission system - has FET control circuit with relay contact in memory circuit

摘要

A pilot control unit for the primary and secondary groups of a data transmission system, has a setting element in the transmission field and a memory preceded by a difference amplifier which is operated by interfering digital pulses. Both the charging and discharging time constants of the memory are along with respect to the pulse duration of the interfering pulses. The setting circuit consists of a field effect transistor (4) with a capacitor (C) connected across the control and the drain electrodes. The control line to the memory incorporates a relay contact (a3). The circuit to the relay coil can also be broken. The relay coil (A) can be connected across the supply.