Single-level LED driving power supply

Abstract

The invention discloses a single-level LED driving power supply which comprises an AC input end, a rectifier circuit, a single-level PFC circuit, a switching element and a feedback control circuit. The AC input end is used for inputting the alternating current supply voltage. The rectifier circuit is connected with the AC input end and used for converting an input full-wave alternating current voltage into a semi-wave alternating current voltage. The single-level PFC circuit is connected with the rectifier circuit and used for rectifying and filtering the semi-wave alternating current voltage output by the rectifying circuit and generating driving currents for driving an LED. The switching element is connected with the single-level PFC circuit and controls on-off of the circuit. The feedback control circuit is connected with the switching element and the single-level PFC circuit and used for feeding back, controlling and adjusting the driving currents and keeping the driving currents constant. The single-level LED driving power supply is simple in structure, low in cost, small in size, capable of feeding leakage inductance energy of a transformer back to the current input end and improving the working efficiency of a convertor and capable of avoiding voltage spike across the two ends when a switching tube is turned off without adding an extra circuit.

Description

technical field [0001] The invention relates to a power drive circuit, in particular to a single-stage LED drive power supply with a leakage inductance energy feedback path. Background technique [0002] Since the isolated LED (Light-Emitting Diode, light-emitting diode) driver has the advantages of low cost and simple system, its application in various AC-DC (Alternating Current-Direct Current, AC-DC power supply) lighting products has attracted attention. More and more attention. For multiple output and safety considerations, LED drive power generally uses a Flyback converter, which requires constant current control to ensure LED operating characteristics. At present, the drive power supply for such devices on the market cannot use the leakage inductance energy of the transformer. Generally, the work efficiency is low, the components are many, and the volume is large. In addition, other circuits need to be added to eliminate the drain-source voltage spike when the MOSFET ...

AI Technical Summary

Problems solved by technology

At present, there are driving power supplies for such devices on the market. The leakage inductance energy of the transformer cannot be used. Generally, the work efficiency is low, the components are many, and the volume is large. In addition, other circuits need to be added to eliminate the drain-source voltage peak when the MOSFET tube is turned off.

This type of old driving power supply has no advantage in small and medium power applications

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