Remote Control Tester and Infrared Detector Card
Handy, easy to use remote control tester and infrared detector in a durable plastic laminated card. Infrared (IR) output from your remote control is indicated by green light on the card. Simple design has no complicated circuitry, needs no batteries and it will operate indefinitely. Broad sensitivity range of 700nm to 1500nm detects the Near Infrared (NIR) range used in most common infrared devices.
How does it work?
The target area of the card has a thin layer of rare earth crystals on it. The crystals are very small, each one being no more than 5 microns in size. When viewed in normal light they are pale lime green in color and are totally safe and non-toxic. To make these crystals do their thing they must first be "charged" with a light source. You can use any light. We find that a fluorescent light is best. Charging saturates the crystals with photons that are trapped and held. Some of these trapped photons manage to escape without help and they may be seen as a slight lime green glow when the card is moved away from the charging light source.
Now that the card is charged it is ready to test your remote control. Remote controls emit low levels of diffused IR so the card needs to be held in a shaded area away from direct light for optimum results. Aim the remote control at the target on the card at a distance of 1 or 2 inches. Test your remote control by pressing its buttons. IR output from your remote control causes the release of the photons trapped in the crystals. Those photons are seen as a bright kryptonite green colored glow in the target area of the card. After about 5 seconds of exposure to infrared light the crystals have released all of their trapped photons and they will need to be charged again to continue testing.
We need to mention a few pointers here.
- Make sure you are using fresh batteries for your test. Weak batteries may not produce enough IR to release enough photons to see any green light.
- If your remote control has a lens on the front, be aware that the actual IR emitter may not be in the center of the lens. Some remote controls will have one IR emitter on each side of the lens. You may need to move the remote control around to locate exactly where the emitter is.
- All remote controls send their commands in a series of very fast on/off pulses of IR. Persistence of vision will cause the very fast pulses to appear as a steady light. Some brands of remote controls steadily repeat the command pulses for long as you hold the button down. Others will send the command stream once and you have to press the button again to send the command again. Still others will continously repeat the command with a short rest between repeats as long as you hold the button causing the target area to flash on and off.
- Some buttons such as the ones that change the function of your remote control from TV operation to DVD operation are simply changing internal functions in the remote control and do not send any commands via IR.