Ultrasonic remote controller for power supply switching - has transmitter and tone decoder operated by keys

摘要

The ultrasonic remote controller for switching power supplies is esp. suitable for the automatic shutting down of heating, lighting etc. when premises are not in use. The controller may be brought into operation by the use of a latch-key for example. The operation of a switch triggers a multivibrator and timer to operate an analogue gate. This allows the output of a tone generator to be connected to an ultrasonic transmitter. One or several receivers detects the radiation and the amplified signal passes to a tone decoder. The decoder employs a phase-locked loop and on correct reception of the two-tone signal, a flip-flop is triggered. This in turn energises a transistorised relay whose contacts connect or disconnect the mains power supply to the various loads.