the television

Who invented the first remote controller has not test, but the earliest one of the remote controller, is called a Nicola Tesla ( Nikola Tesla ) ( 1856-1943 ) inventor ( he used to work for Edison, also known as a genius inventor) in 1898 developed ( USA Patent No. 613809) called” Method of and Apparatus, for Controlling Mechanism of Moving Vehicle or Vehicles”.

The earliest used to control the television remote controller is an American called Zenith electrical company ( the company is now LG acquired ),dvb t tuners
in 1950 time development. Started as a cable. In 1955, the company developed a method called ” Flashmatic” wireless remote control device. But this device could not tell whether the beam from the remote control, but also the necessary alignment can control.

1956 rob. Adler ( Robert Adler ) developed called” Zenith Space Command” remote control, this is also the first modern wireless remote control device, he is using ultrasound to adjust channel and volume, each key produces frequency is not the same, but this device may also be a general ultrasonic interference, but also some people and animals ( such as dogs ) hear the voice remote control.

In 1980, sending and receiving infrared semiconductor device developed, gradually replaced the ultrasonic control device. Even though the other wireless transmission means (such as Bluetooth ) continue to be developed, this technology still continued widespread use.

Working principle

A : infrared remote control principle

Many electrical appliances are the use of infrared remote control infrared remote control, then what is the working principle? First of all we have to have a look what is infrared ray.

The human eye can see visible light according to wavelength from long to short order, followed by red, orange, yellow, green, cyan, blue, purple.dvb t receivers
The red light wavelength in the range of 0.62 ~ 0.76 m; purple light wavelength in the range of 0.38 ~ 0.46 M. Violet wavelength shorter than light ultraviolet, than red light with a wavelength of long light called infrared.

Infrared remote control is the use of a wavelength of 0.76 1.5 ~ m between near infrared light to transmit a control signal.

Common infrared remote control system in general is divided two parts: sender and receiver.

The transmitter portion of main components for the infrared light emitting diode. It is actually a special light emitting diode, due to its internal material differs from the ordinary light-emitting diode, which at its ends to exert a certain voltage, it emits infrared rather than visible light.

The current extensive use infrared light-emitting diodes to emit an infrared wavelength is about 940nm, the same general shape and light emitting diode,cable supplier but different colours.

Infrared light emitting diode are generally black, dark blue, transparent three colors.

Judge infrared emitting diode quality approach and judging normal diode: using a multimeter to measure resistance block the infrared light emitting diodes, reverse resistance can be positive.

Infrared light emitting diode luminous efficiency should use special instruments can be accurately determined, and amateur conditions can only pull distance method to judge roughly. The receiving part of the infrared receiving tube is a photosensitive diode.

In practical application to the infrared receiving diode reverse bias, for it to work properly, or infrared receiving diode on the circuit in the application of reverse use, so as to obtain high sensitivity.

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