Characteristics and applications of diodes

Diode is an electronic device made of semiconductors. It has unidirectional conductivity, which is usually called rectification. It can convert alternating current into pulsating direct current, such as modulating radio signals by a radio receiver through rectification.

Under the action of the forward voltage, the resistance of the diode is very small and in the on state; under the action of a reverse voltage, the resistance is very large and is in the off state. Using the switching characteristics of diodes, various logic circuits can be formed. The use of semiconductor diodes in circuits can protect the circuit and prolong the life of the circuit.

Zener diode is a special surface contact type semiconductor silicon diode, which works in reverse breakdown state and has the function of stabilizing voltage. The reverse breakdown voltage is constant, and a current-limiting resistor is connected in series in the voltage regulator circuit to make the current after the voltage regulator tube breakdown does not exceed the allowable value, so the breakdown state can last for a long time without damage.

In electronic circuits, limiter circuits are commonly used to process various signals. It is used to selectively transmit part of the signal within a preset level range. Most diodes can be used as limiters, but sometimes special limiter diodes are needed, such as when protecting meters.

In almost all electronic circuits, semiconductor diodes are indispensable, and their application range is very wide. There are diode traces in the chargers of mobile phones and portable devices, radio circuits, household appliances or industrial control circuits. Reasonable connection with resistors, capacitors, inductors and other components can form circuits with different functions to achieve various functions such as AC rectification, modulation signal detection, limiting and clamping, and power supply voltage stabilization.

In the application of industrial products, light-emitting diodes are widely used in indicator lights of various electronic products, light sources for optical fiber communication, indicators and lighting of various meters. Our commonly used LCD TVs, computer displays, mobile phones, etc. all use light-emitting diodes as the screen backlight. In addition, light-emitting diodes are used in car lights, mechanical equipment and instrument lighting, miners' lights and lighting equipment. In addition, based on its long life, energy saving, easy drive and control, and maintenance-free features, light-emitting diodes are replacing neon lights.