Power supply circuit for electronic ballast control chip

Abstract

The invention relates to a power supply circuit for an electronic ballast control chip, comprising an EMI filter circuit, a rectifying circuit, a power factor correction circuit, a ballast control circuit, an output-level circuit and a chip power-supply circuit, wherein the input end Net1 of the chip power-supply circuit is connected with the output-level circuit, and is sequentially connected with a coupling capacitance C1 and a rectifier diode D1; the cathode of the rectifier diode D1 is sequentially connected with a rectifier diode D2, a filter capacitance C2, and is respectively connected with an adjusting triode Q1 collector and one end of a resistor R1; the other end of the resistor R1 is respectively connected with the adjusting triode Q1 base, a stabilizing diode Z1 cathode and a stabilizing diode Z2 cathode; the adjusting triode Q1 emitter sequentially is connected with the adjusting triode Q1 base through a current-limiting resistor R2 and the stabilizing diode Z2; and the stabilizing diode Z2 anode is respectively connected with the other end of a resistor R3, an energy storage capacitance C3 anode and an output VCC.

Description

【Technical field】 [0001] The invention relates to an electronic ballast circuit, in particular to a power supply circuit for an electronic ballast control chip, which is applied to an electronic ballast for fluorescent lamps in a series resonance working mode. 【Background technique】 [0002] At present, mature and reliable electronic ballast circuits generally use professional electronic ballast control chips, such as L6574D, IR21592, etc. The front-end PFC circuit uses professional PFC control chips, commonly used chips such as L6561, UC3854, MC34262, etc. [0003] However, providing a stable power supply for the chip used in the electronic ballast is the key to the stable and reliable operation of the ballast as a whole. Although the use of a special power supply control circuit is reliable, the cost is too high, and the overall electrical efficiency of the ballast is reduced, and the use of a simple power supply circuit will affect the reliability of the circuit. [0004...

AI Technical Summary

Problems solved by technology

[0006] First, the power chip power supply method is used, and the cost is relatively high;

[0007] Second, when the circuit is abnormal, although the electronic ballast will not be damaged after the circuit enters the protection through the abnormal protection circuit, the PFC chip and the ballast control chip are still working, which increases the standby power consumption;

[0008] Third, the power chip power supply mode, due to the increase in the complexity of the circuit structure, the overall electrical efficiency of the ballast will decrease

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