Open circuit protection circuit for self-ballasted fluorescence

Abstract

The invention discloses an open circuit protection circuit for self-ballasted fluorescence. The open circuit protection circuit comprises a silicon controlled rectifier SCR1, a bidirectional diode DB2, a winding N4 and a rectifier bridge BR1, wherein the anode of the silicon controlled rectifier SCR1 is connected with the positive electrode of an external power source, the cathode of the silicon controlled rectifier SCR1 is connected with the negative electrode of the external power source, the control electrode of the silicon controlled rectifier SCR1 is connected with the bidirectional diode DB2 in series and then connected with the sampling voltage output end, the winding N4 and a primary feedback winding N2 of a self-ballasted fluorescence lamp are coupled to form a transformer, the two ends of the winding N4 are connected with the two alternating current input ends of the rectifier bridge BR1, one direct current output end of the rectifier bridge BR1 is connected with the negative electrode of the external power source, and the other direct current output end of the rectifier bridge BR1is connected with the anode of the silicon controlled rectifier SCR1. By the adoption of the open circuit protection circuit, self-exciting oscillation of the circuit can be rapidly stopped when loads of the self-ballasted fluorescence lamp circuit are in an open circuit, and the open circuit protection effect is achieved.

Description

technical field [0001] The invention relates to the field of electronics, in particular to an open circuit protection circuit for a self-ballasted fluorescent lamp. Background technique [0002] Self-ballasted fluorescent lamps, also known as energy-saving lamps, have been widely used in human daily life lighting and industrial lighting. Generally speaking, the self-ballasted fluorescent lamp circuit is a self-oscillating circuit. When the load at the output end of the circuit is open, the output end still has a voltage output. Due to the working characteristics of the ballast circuit, the voltage at the output end is normal when the load is open. Several times of the working voltage can reach hundreds of volts, which is not only unfavorable to the main circuit, but also brings the danger of electric shock to the operator. Contents of the invention [0003] The technical problem to be solved by the embodiments of the present invention is to provide an open-circuit protect...

AI Technical Summary

Problems solved by technology

Generally speaking, the self-ballasted fluorescent lamp circuit is a self-oscillating circuit. When the load at the output end of the circuit is open, the output end still has a voltage output. Due to the working characteristics of the ballast circuit, the voltage at the output end is normal when the load is open. Several times the working voltage, up to hundreds of volts, not only unfavorable to the main circuit, but also bring the danger of electric shock to the operator

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