Infrared Technology for Remote Controls Overview

General Description of Infrared Technology


Many remote controls use infrared light as a method for communicating commands from the hand held remote control to the device being controlled, such as a television.


What is Infrared (IR) light?

Infrared light is a form of electromagnetic radiation. There are visible forms of light and then there are forms of light not visible to the human eye. Infrared light falls into the later category as so is not visible to the human eye. The infrared light wavelength starts at 700nm.

There are many applications and devices that use some form of infrared light. Remote controls typically use a narrow band of the infrared range.

Using electronic circuits and components we can control the frequency and format of infrared transmissions from a remote control. Many device manufacturers have selected specific protocols they use for the the devices they manufacture and are controlled by an infrared remote. For example Sony has a specific protocol used in most of the devices they manufacture that use a remote control. In order to control a Sony device a remote control must not only send out an infrared signal using the correct Sony protocol, the infrared code must also be formatted in a very unique pattern. Each function on a device will have a unique infrared code pattern associated with it. A 'power' command will be different from a 'volume up' command. Usually manufacturers of devices will try to ensure the code patterns for their device do not interfere with the infrared code patterns from other manufacturers. This is done so that you don't get unwanted results with multiple infrared controlled devices in one room.



What are the advantages of Infrared for Remote Controls?

Availabilty and Cost -

Infrared technology for controlling electronic devices has been available for many years. As such it is a very robust and tested technology. Each command can be very unique as there are unlimited ways to structure infrared codes and protocols. Many many devices have been manufactured to use infrared remote controls and millions of remote controls have been manufactured. Since the technology is common and robust the electronic components used in the design and manufacture of infrared remote controls are readily available and relatively inexpensive. As with any technology and components there are high quality components that may cost more than low quality, similar components.

Line of Sight -

Another advantage of using infrared technology is that it is used for line of sight applications. Since infrared light is a light source, it cannot go through solid, opaque objects such as walls. The remote control must be in the same room, and be in range, of the device it is controlling. This limits interference if two of the same device are located in the same house, but not in the same room. There are special electronic devices called 'repeaters' which are designed to 'see' and infrared code and then transmit that infrared code using a different technology such as radio frequency, to a second device which translates the signal back into the correct infrared code. These devices are used to bypass the line of sight concept. These devices, as well as radio frequency remote controls are more expensive than a typical infrared remote control. While line of sight is an advantage for some applications, it can be a disadvantage. Some applications require the individual using the remote control to be in line of sight of the device being contorolled. Using infrared technology usually ensure the operator is in the same room and in close proximity (30 feet or so) of the device being controlled.

Range -

A typical infrared remote control using two AAA batteries has a typical range of 30 feet. Sometimes more, sometimes less. 30 feet is usually more than adequate for use in a room of a house for watching television, using a cable box, set top box, satellite dish, controlling stereo components etc. This has for many years been the typical environment for using a remote control. Most people do not sit more than 30 feet from their television! However, technology is changing. People want to hide their electronic components behind cabinets or in closets. Cabinets and closets typically block the infrared light from reaching the device so repeaters have been developed, or, remote controls are moving towards using radion frequencies. Radio frequency signals can penetrate through solid objects (with some limitations). Radio frequency can also provide a greater range or distance of transmission. However, radio frequency is usually more expensive to manufacure, and can also use more power from batteries (standard alkaline, lithium or rechargeable).

Certifications -

Infrared technology is usally a very low power technology and does not output emissions that could interfere, even accidentally, with other devices. As such there are few global regulatory requirements for infrared technology. This is not the case with radio frequency technology. Please contact us for further details.

Should you use an infrared remote control for your electronic product, or another transmission technology such as radio frequency?

This will depend on your application and budget. If the device to be controlled will always be, or must be, within line of sight of the person using the remoKeep in mind that your device must include a receiver that will see and decode the signal from the remote control. Infrared receiver technology is also usually less expensive than radio frequency receivers, and is less succeptable to antenna and other radio frequency interference.















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Copyright 2016. All Rights Reserved.

This site is an information site hosted by Celadon, Inc., manufacturer of infrared remote controls, radio frequency remote controls (RF remotes), infrared receivers, and radio frequency receivers. Please visit either www.celadon.com, or, www.infraredremotes.com for more specific remote control product information.

Please contact Celadon, Inc. should you have any questions regarding infrared or radio frequency remote controls or related remote control products.