Suitable for any Infrared emitting device, 3V battery supply. A very simple device allowing a quick check of common Infra-red Remote-Controls can be useful to the electronics amateur, frequently asked to repair or test these ubiquitous devices. A reliable circuit was designed with a handful of components: the LED will flash when any of the Remote-Control push buttons will be pressed. The side of the Remote-Control bearing the IR emitting diode(s) must be directed towards the Photo Transistor (Q1) of the checker circuit: maximum distance should not exceed about 20 - 25cm. . Circuit Diagram: Infrared Remote Tester Circuit Diagram Parts: R1 = 470K R2 = 47R D1 = LED Any Type Q1 = Photo Transistor Q2 = BC327 B1 = 3V Battery or 2 AA cell Notes: Current drawing of the circuit is less than 1mA when the LED illuminates and 0mA when no signal is picked-up by the Photo Transistor: therefore, SW1 can be omitted. SW1 will be SPST Toggle or Slider Switch Sourced By: Streampowers