Radio wireless remote control circuit b

The receiver circuit principle is shown in the figure. Insert the plug XP into the headphone socket xs of the radio. When the radio receives the signal from the transmitter, the
audio signal output from
The base is turned on, and the relay KD is therefore closed. KD pulls in, and its normally open and normally closed contacts can be used to connect to any load circuit to achieve wireless remote control
of turning on or off .