Remote control

From Wikipedia, the free encyclopedia

For other uses, see Remote control (disambiguation).

A television remote control

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

The term, sometimes abbreviated to "remote" and also called a "controller", "flipper", "clicker", or "changer" 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/socket. Remote controls for these devices are usually small wireless 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.

1 History
2 Technique
3 Usage
4 See also
- 4.1 Products and standards
5 External links

[edit] History

One of the earliest examples of remote control was developed in 1893 by Nikola Tesla, and described in his patent, U.S. Patent 613809, named Method of and Apparatus for Controlling Mechanism of Moving Vehicle or Vehicles.

In 1903, Leonardo Torres Quevedo presented the Telekino at the Paris Academy of Science, accompanied by a brief, and making an experimental demonstration. In the same year, he obtained a patent in France, Spain, Great Britain, and the United States. The Telekino consisted of a robot that executed commands transmitted by electromagnetic waves. It constituted the world's first apparatus for radio control and was a pioneer in the field of remote control. In 1906, in the presence of the king and before a great crowd, Torres successfully demonstrated the invention in the port of Bilbao, guiding a boat from the shore. Later, he would try to apply the Telekino to projectiles and torpedoes, but had to abandon the project for lack of financing.

The first remote-controlled model aeroplane 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.

Image:Zenith SpaceCommand.jpg

The Zenith Space Command remote control

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. [1]

Image:Core remote.gif

In the 80’s Steve Wozniak of Apple, started a company named CL9. The purpose of this company was to create a remote control which controlled multiple electronic devices. The CORE unit as it was named (Controller Of Remote Equipment) was introduced in the fall of 1987. The advantage to this remote controller was that it could “learn” remote signals from other different devices. It also had the ability to perform specific or multiple functions at various times with its built in clock. It was also the first remote control which could be linked to a computer and loaded with updated software code as needed. The CORE unit never made a huge impact of the market. It was much too cumbersome for the average user to program, but it received rave reviews from those who could figure out how to program it. These obstacles eventually lead to the demise of CL9, but one of its employees continued the business under the name Celadon. This was one of the first computer controlled learning remote controls on the market. [2]

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 [3], a renowned usability specialist and Robert Adler, the inventor of the modern remote, note how confusing, unwieldy and frustrating the multiplying remotes have become.

[edit] Technique

Image:Control-remote-spectrum.png

Image:Remote control infrared animated.gif

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, as well as by the sensor of a digital camera.

With a single channel (single-function, one-button) remote control the presence of a carrier signal can be used to trigger a function. For multi-channel (normal multi-function) 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. One can often hear the signals being modulated on the infrared carrier by operating a remote control in very close proximity to an AM radio not tuned to a station.

[edit] Usage

[edit] 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..

[edit] Emergency

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

[edit] Military

Soviet Red Army used remotely controlled teletanks during 1930s in the Winter War and early stage of World War II. A teletank is controlled by radio from a control tank at a distance of 500–1,500 meters, the two constituting a telemechanical group. Teletanks were used by the Soviet Red Army in the Winter War and fielded at least two teletank battalions at the beginning of the Great Patriotic War. There were also remotely controlled cutters and experimental remotely controlled planes in the Red Army.

[edit] 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.

[edit] Video games

Most video game consoles used wired controllers until recently, mainly because of the difficulty involved in playing the game while keeping the infrared transmitter pointed at the console. Some wireless controllers were produced by third parties, in most cases using a radio link instead of infrared. 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 Wii.