A pair of PCB, one a transmitter and receiver, transmits an infra-red beam about 5 metres. And if the beam is broken by anything or anybody, the receiver-board switches a relay. (5Amps, 220Vac). Operating voltage: 9V to 12Vdc.
EFK 12000 Just Whistle
EFK 12002 Infra -Red Remote Control
EFK 12004 Telephone Line Recording Switch
EFK 12005 Sound-Activated Switch
EFK 12006 Touch Activated Switch