Simple IR Remote Tester

Most cases of infra-red remote control failure can be detected by detecting the absence of the pulsed transmitted infra red light. It’s very rare that the remote control fail while it is still capable of transmitting the infrared pulse.  This condition enable such a very simple tester is easy to build. A simple infrared detector with ac coupling and simple amplifier can be built with a photo-diode and two small transistors. The photo-diode should be a 940nm type to match the infrared response. The type of the transistors are not crucial, almost any small transistor with 100x gain and 100 mA collector current can be used. This remote control tester circuit will operate from a 6 to 12 V rails power supply. A quick initial blink of the indicator LED will give a battery self test when we switch the switch to turn on this tester. Here is the circuit’s schematic diagram: