You might not be familiar with what infrared LED is, but chances are you're familiar with the devices where they're used. An infrared LED is a tiny "light emitting diode" used to power devices such as remote controls. The wavelength transmitted by infrared light carries a signal that tells devices what to do (such as, with the remote, telling it to change the TV channel).
Differences between Infrared & Visible Light LEDs
There are a few primary differences between infrared LEDs and visible light LEDs, especially pertaining to their electrical characteristics. For instance, an infrared LED has a lower forward voltage than the visible light LED does. It also has a higher rated current. This is because of differences in the properties of the junction. A normal infrared LED drive current might be as much as 50 milliamps, so it's usually not wise to drop in a visible LED to replace a bad infrared LED.
Common Applications
While the LED IR light is, as mentioned, used in remote controls, a more common application is in security devices. That's because the light can't be seen. Infrared lights are produced with wavelengths that range from 8330 to 959 nanometers. This is not a wavelength visible by the human eye. It makes the IR LED perfect for use with alarm systems, Closed-circuit TV systems, video cameras, and for night vision products.
Consumer's Tips
Infrared LED lights come with different numbers of LEDs installed, depending on the application. The more LEDs, the greater the intensity of the lights within the viewing angle. You should use an IR light pulser to increase the IR light's effective range. These pulsers literally "pulse" the infrared light at a higher current. This is sometimes ten times as high as that produced by a normal DC power supply. A poor match of light and LED pulser might cause permanent damage to your infrared LEDs.
Before you buy an infrared LED light, remember to do the following:
1) Be sure it has a radiated wavelength of less than 880nm.
2) Go with at least a 60 degree viewing angle--or better.
3) Remember that more LEDs will mean more luminance, not more range.
4) Use an IR light pulser to get longer range.
One Innovative Use: Light Therapy
We haven't touched on one innovative use of IR LED light, which has popped up just in the past few years. IR LEDs are now starting to replace lasers for use in light therapy. These are being used by dermatologist to do all sorts of reconstructive work on the patient's skin.
There are definite advantages to using IR LED light rather than lasers for light therapy. For starters, the treatments aren't as expensive to prepare. Plus, there is the possibility, especially as the technology develops, that LED light will be able to pierce deeper under the skin, safer, than with lasers. All of this is just further evidence that the full potential of the infrared LED has only begun to be tapped.
|
|