With the aid of this circuitry it is made possible to carry out functional tests of infrared remote controls used in TV-sets and video devices, etc. Whenever there is radiation of infrared beams on the Special-Sensor, the LED will light up and indicate that the infrared remote control is operated. As accessories is available our kit "B 197 Relay Card". This could be connected with the Infrared Detector and it is then possible to switch through the relay contact loads up to 3 A.