RECORD LEVEL INDICATOR CIRCUIT

摘要

An incandescent indicator lamp is connected in series with an SCR across an AC electrical power source. The gate terminal of the SCR is coupled through a voltage dividing network to a lead which is connected to a recording amplifier for monitoring a communication signal. The voltage dividing network is set to cause the SCR to be triggered for enabling conduction, thereby enabling current flow therethrough to light the indicator lamp, whenever the amplitude of the monitored communication signal is of at least a predetermined record level.