Infrared Remote Control Principle

Many electrical appliances are infrared remote control, then infrared remote control of the working principle of what? First we look at what is infrared.

People's eyes can see the visible light from the length to short arranged, in turn red, orange, yellow, green, green, blue, purple. The wavelength range of red light is 0.62~0.76 μ m; the wavelength range of violet is 0.38~0.46 μ m. The light that is shorter than the violet wavelength is called ultraviolet ray, which is called infrared ray longer than the red wavelength.

Infrared remote control is the use of the wavelength of the near infrared ray between 0.76~1.5 μ-m to transmit the controlled signal.

Commonly used infrared remote control system to transmit and receive two parts.

The main components of the transmitting part are IR LEDs. It is actually a special light-emitting diode, because its internal material differs from the ordinary light-emitting diode, so it emits an infra-red instead of visible light when a certain voltage is applied at both ends.

A large number of infrared light emitting diodes emit the infrared wavelength of 940nm or so, the shape is the same as the ordinary light-emitting diode, but the color is different.

IR LEDs generally have black, dark blue, transparent three colors.

The method of judging infrared light emitting diode is the same as judging ordinary diode: the positive and reverse resistance of infrared light emitting diodes can be measured by the electric blocking of the multimeter.

The luminous efficiency of IR LEDs should be precisely determined by special instruments, but only by the drawing-distance method in amateur conditions. The receiving portion of the IR receiver is a photosensitive diode.

In the actual application to the infrared receiver diode reverse bias, it can work normally, that is, the infrared receiver diode in the circuit application is reversed, so that the high sensitivity.

IR receiver diodes generally have both circular and square shapes.