What is a freewheeling diode, its structure, principle, function, type, operating procedures, and development history 1

A freewheeling diode is a semiconductor device with bidirectional conductivity, also known as a capacitor diode or a forward and reverse parallel thyristor. It is usually used in parallel with AT24C04BN-SH-T switch tubes or other power devices in circuits to eliminate reverse high-energy pulses and prevent reverse breakdown, thereby improving the stability and reliability of the system. Its main function is to provide a controllable conduction path in AC circuits to achieve precise control of current. The following is a detailed explanation about the freewheeling diode:

1、 Structure:

The structure of a freewheeling diode is similar to that of a regular diode, mainly composed of P-type and N-type semiconductors connected by a PN junction, but its special design allows it to withstand reverse high voltage. They are generally made of silicon materials because silicon diodes have high withstand voltage and low forward voltage drop.

2、 Principle:

The working principle of a freewheeling diode is based on the unidirectional conductivity of a PN junction. When operating an inductive load, the freewheeling diode is connected in reverse parallel at both ends of the load. When the circuit is powered on, the freewheeling diode is in a reverse cutoff state, which does not affect the normal operation of the circuit; When the circuit is disconnected, the high reverse voltage released by the inductor causes the freewheeling diode to quickly turn on, forming a circuit that safely releases the current released by the inductor, thereby protecting the circuit from damage.

3、 Function:

Continuous current diode can be used as auxiliary components for overvoltage protection, energy recovery, and resonant circuits, and are widely used in the field of power electronics.

4、 Type:

Freewheeling diode can be classified according to different standards, such as silicon diodes, Schottky diodes, etc., based on their materials; According to the withstand voltage level, it can be divided into low voltage, medium voltage, and high voltage freewheeling diodes; According to the packaging form, it can be divided into various types such as surface mount (SMD) and direct insertion (DIP).