LED surge protection circuit based on voltage dependent resistors

Abstract

The invention provides an LED surge protection circuit based on voltage dependent resistors. The LED surge protection circuit comprises a full-bridge rectifier bridge pile, a current-limiting resistor, a filtering capacitor C2, a filtering capacitor C3, a voltage-reducing capacitor C1, a resistor R1, a resistor R2 and three voltage dependent resistors. The DC output positive electrode of the full-bridge rectifier bridge pile is connected with the positive electrode of an LED load via the current-limiting resistor, and the DC output negative electrode is connected with the negative electrode of the LED load. The filtering capacitor C2 and the LED load are connected in parallel. One end of the filtering capacitor C3 is connected with the DC output positive electrode of the full-bridge rectifier bridge pile, and the other end is connected with the negative electrode of the LED load. The three voltage dependent resistors are respectively connected between the zero wire of commercial power and the live wire of commercial power, between the live wire of commercial power and a grounding wire, and between the zero wire of commercial power and the grounding wire. According to the drive circuit, one voltage dependent resistor is connected in parallel in each phase wire and the zero wire so that burnout of the drive circuit and the LED load caused by surge can be prevented, and thus the LED surge protection circuit has a surge protection function.

Description

technical field [0001] The invention relates to the technical field of LED drive circuits, in particular to an LED surge protection circuit based on a piezoresistor. Background technique [0002] LED is a semiconductor light-emitting diode. The core part of a light-emitting diode is a wafer composed of a p-type semiconductor and an n-type semiconductor. There is a transition layer between the p-type semiconductor and the n-type semiconductor, which is called a PN junction. In the PN junction of some semiconductor materials, when the injected minority carriers recombine with the majority carriers, the excess energy will be released in the form of light, thereby directly converting electrical energy into light energy. When a reverse voltage is applied to the PN junction, it is difficult for minority carriers to inject, so it does not emit light. This kind of diode made using the principle of injection electroluminescence is called light-emitting diode, commonly known as LED. ...

AI Technical Summary

Problems solved by technology

The light emission of LED energy-saving lamps is driven by its drive circuit. Since the drive circuit is directly connected to 220V AC, the surge in the power grid is easy to burn out the drive circuit and LED load. Although there is a surge, the probability of the surge is not high. If Configuring a special anti-surge surge protector will lead to higher circuit costs, and the role of the surge protector is not obvious, resulting in lower cost performance of the circuit

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