Semiconductor Knowledge: Principles and Functions of Zener Diodes

It's time for a day long semiconductor knowledge section. Looking back at the previous issue, the editor shared the principle of overheating failure of fast recovery diodes. Generally, damage to fast recovery diodes is located at the edge of the equipment. Today, we will still talk about diodes, the principle and function of voltage regulator diodes.

A voltage regulator diode is a semiconductor device that has a high resistance before the critical reverse breakdown voltage, and the reverse resistance drops to an extremely low value at the critical breakdown point. When the current increases, the voltage remains unchanged, and the voltage regulator diode is divided according to the breakdown voltage. For this reason, zener diodes are mainly used as voltage regulators or voltage reference devices. Voltage stabilizing diodes can be connected in series to operate at high voltages, obtaining a higher stable voltage through series connection.

Overvoltage protection circuit in TV: 115V is the main power supply voltage of the TV. When the output voltage of the power supply is too high, D conducts and the transistor T conducts, the collector potential will change from the original high level to low level, and the voltage of the TV on the standby control line will be converted to the standby protection state.

Arc suppression circuit: If a suitable voltage regulator diode is connected in parallel to the inductance coil, when the coil is cut off in a conductive state, the high voltage generated by the electromagnetic energy release is absorbed by the diode. Therefore, when the switch is disconnected, the arc of the switch is eliminated.

In addition to manufacturing stable circuits, voltage stabilizing diodes can also be used as disposable protective circuits. For example, in important locations, it is prohibited to increase voltage to damage valuable equipment, and a voltage regulator can be used in reverse parallel. When a power failure occurs, after exceeding the voltage stabilizing capacity of the voltage stabilizing tube, the voltage stabilizing tube quickly switches from the cut-off state to reverse breakdown, directly shorting the power supply and protecting all loads of the power supply branch from being damaged due to overvoltage. Because the voltage regulator used for this type of protection is usually not working, it can be temporarily not used during emergency maintenance. Experienced maintenance personnel can even use local materials in emergency situations and can flexibly use them as maintenance tools after disassembly and assembly.

The above is about the function of a voltage regulator diode. For more information on the selection and specifications of semiconductor products such as diodes, transistors, and MOS transistors, please follow Frexin. Click to consult customer service for collection, bringing you more information about the semiconductor industry.