Remote control

A remote control is an electronic device used for the remote operation of a machine.

The term, sometimes abbreviated to “the remote” and also called a "flipper" or "clicker", is most commonly used to refer to a remote control for televisions or other consumer electronics such as stereo systems and DVD players, and to turn on and off a mains plug. Remote controls for these devices are usually small handheld objects with an array of buttons for adjusting various settings such as television channel, track number, and volume. In fact, for the majority of modern devices with this kind of control, the remote contains all the function controls while the controlled device itself only has a handful of essential primary controls. Most of these remotes communicate to their respective devices via infrared (IR) signals and a few via radio signals. They are usually powered by small AAA or AA size batteries.

History

One of the earliest examples of remote control was developed in 1893 by Nikola Tesla, and described in his patent, , named Method of and Apparatus for Controlling Mechanism of Moving Vehicle or Vehicles. The first remote-controlled model airplane flew in 1932. The use of remote control technology for military purposes was worked intensively during the Second World War, one result of this was the German Wasserfall missile. The first remote intended to control a television was developed by Zenith Radio Corporation in the early 1950s. The remote — unofficially called “Lazy Bones” — used a wire to connect to the television set. To improve the cumbersome setup, a wireless remote control was created in 1955. The remote called “Flashmatic” worked by shining a beam of light onto a photoelectric cell. Unfortunately, the cells did not distinguish between light from the remote and light from other sources. The Flashmatic also required that the remote control be pointed accurately at the receiver.

In 1956 Robert Adler developed “Zenith Space Command”, a wireless remote. It was mechanical and used ultrasound to change the channel and volume. When the user pushed a button on the remote control it clicked and struck a bar, hence the term “clicker”. Each bar emitted a different frequency and circuits in the television detected this noise. The invention of the transistor made possible cheaper electronic remotes that contained a piezoelectric crystal that was fed by an oscillating electric current at a frequency near or above the upper threshold of human hearing, though still audible to dogs. The receiver contained a microphone attached to a circuit that was tuned to the same frequency. Some problems with this method were that the receiver could be triggered accidentally by naturally occurring noises, and some people, especially young women, could hear the piercing ultrasonic signals. There was even a noted incident in which a toy xylophone changed the channels on these types of TVs since some of the overtones from the xylophone matched the remote’s ultrasonic frequency.

The impetus for a more complex type of television remote control came in the late 1970s with the development of the Ceefax teletext service by the BBC. Most commercial remote controls at that time had a limited number of functions, sometimes only four: next station, previous station, increase or decrease volume. This type of control did not meet the needs of teletext sets where pages were identified with three-digit numbers. A remote control to select teletext pages would need buttons for each number from zero to nine, as well as other control functions, such as switching from text to picture, and the normal television controls of volume, station, brightness, colour intensity and so on. Early teletext sets used wired remote controls to select pages but the continuous use of the remote control required for teletext quickly indicated the need for a wireless device. So BBC engineers began talks with one or two television manufacturers which led to early prototypes in around 1977-78 that could control a much larger number of functions. ITT was one of the companies and later gave its name to the ITT protocol of infrared communication. ^*

In the early 1980s, when semiconductors for emitting and receiving infrared radiation were developed, remote controls gradually switched to that technology which, as of 2006, is still widely used. Remotes using radio technologies, such as Bose Audio Systems and those based on Bluetooth also exist.

By the early 2000s, the number of consumer electronic devices in most homes greatly increased. According to the Consumer Electronics Association, an average American home has four remotes. To operate a home theater as many as five or six remotes may be required, including one for cable or satellite receiver, VCR or digital video recorder, DVD player, TV and audio amplifier. Several of these remotes may need to be used sequentially, but, as there are no accepted interface guidelines, the process is increasingly cumbersome. Many specialists, including Jakob Nielsen ^*, a renowned usability specialist and Robert Adler, the inventor of the modern remote, note how confusing, unwieldy and frustrating the multiplying remotes have become. To that end, designers of the TiVo remote control replaced the standard columns of buttons on a black rectangle with a distinctive peanut shaped design that has been well received by its users. This design, which has spawned several imitations, is likely to change the way consumer electronics designers approach the remote.

Technique

Most control remotes for electronic appliances use a near infrared diode to emit a beam of light that reaches the device. This light is invisible to the human eye but carries signals that are detected by the appliance.

With a single channel remote control the presence of a carrier signal can be used to trigger a function. For multi-channel remote controls more sophisticated procedures are necessary: one consists of modulating the carrier with signals of different frequency. After the demodulation of the received signal, the appropriate frequency filters are applied to separate the respective signals. Nowadays digital procedures are more commonly used.

Usage

Industry

Remote control is used for controlling substations, pump storage power stations and HVDC-plants. For these systems often PLC-systems working in the longwave range are used.

Emergency

Sometimes remotely controlled machinery is nessessary in emergency situation such as radioactive or toxic environment to avoid human casualities to prevent damage to human health. For example, remotely controlled robots were used during liquidation of circumstances of Chernobyl disaster.

Military

Military usage of remotly controlled military vehicles dates back to the first half of 20th century. Red Army used remotely controlled teletanks during 1930 and early stage of World War II. There were also remotely controlled cutters and experimental remotely controlled planes in the Red Army.

Space

Remote control technology is also used in space travel, for instance the Russian Lunokhod vehicles were remote-controlled from the ground. Direct remote control of space vehicles at greater distances from the earth is not practical due to increasing signal delay times.

Video games

Video-games used cables until recently mainly because infrared technollogy wasn't that reliable for playing because of the difficulty of playing and pointing the controller to the sensor at the same time. Many 3rd-party companies made wireless controllers for many consoles, though. The first official wireless controller was the radio waves technology Wavebird for Nintendo Gamecube. After that wireless controllers became standard for the next/current generation of consoles, including the Xbox 360, the PS3 and the Wii.

External links

Description of infrared remote protocols
Infra-red handset technical overview
Infra-red handset signalling systems
Infra-red Remote Control Theory
RemoteCentral.com
Five Decades of Channel Surfing: History of the TV Remote Control
Watchkey
Radio Control - A wiki whose "aim is to be the ultimate knowledge base on everything RC!"

Assistive technology | Consumer electronics | Television technology | Wireless communications | Unmanned vehicles

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