Infrared (IR) transmitters are found in many everyday electronic devices, such as television remote controls. These devices operate in the electromagnetic spectrum's infrared region. An IR transmitter is designed to transmit signals and commands to electronic equipment through infrared waves. Infrared transmitters are short-range communication devices and are not designed for long-range communication.
An IR transmitter can be employed for many applications. Essentially, it is used to give commands to electronic devices from a distance without using cords, cables or wires. Most modern electronic devices are controlled mainly through an IR transmitter, making them remote-control devices. Very few designated buttons make it onto actual modern electronics such as televisions and video game systems.
Televisions, stereos and many video game systems use remote controls with IR transmitters. IR transmitters can be used to adjust volume and change channels on a television or change tracks and discs on a compact disc (CD) or digital versatile disc (DVD) player. Certain light dimmers, garage door openers and even many brands of air conditioners also can be controlled with IR transmitters.
Most IR transmitter devices cannot transmit a signal through walls and floors, but several manufacturers sell extender systems that can be employed to increase the strength and range of an IR transmitter. Linked in with a signal extender, a remote control can be used to turn off a device in one room from several rooms away. In many cases, several components can be linked in with these extender systems to increase the overall strength and range of several IR transmitters at once.
Infrared transmitters operate within the infrared section of the electromagnetic spectrum. The infrared region of this spectrum is located between the visible light and microwave regions of the spectrum. Near infrared light offers wavelengths closer to those of visible light, and far infrared light wavelengths are closer to microwaves on the electromagnetic spectrum. Far infrared waves produce heat, so they can be felt. Near infrared waves, such as the waves produced by the IR transmitters in television remote controls, are shorter than far infrared waves and cannot be felt.
Universal remote controls can be employed to mimic the IR signals produced by most other IR transmitters. In many cases, a universal remote control can take the place of several other IR transmitter controls. Most universal remote control manufacturers design their remote controls with infrared transmitter systems that can read hundreds of IR codes.