A remote control is an electronic device used for the remote operation of a machine. more...
The term, sometimes abbreviated to “the remote”, 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 AA or AAA size batteries.
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. The first remote controlled model airplane flew 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”, the first 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 tones from the xylophone matched the remote’s ultrasonic frequency.
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