LED driver for chopping light adjustment occasion

Abstract

The embodiment of the invention discloses an LED driver for a chopping light adjustment occasion, and the driver comprises a rectification circuit and a DC-DC conversion circuit, wherein the rectification circuit and the DC-DC conversion circuit are sequentially connected between a phase angle light modulator and an LED load; and a current circuit which is in parallel connection with an output side of the rectification circuit, wherein the current circuit comprises an impedance circuit, an auxiliary source circuit, and a current circuit switching unit. A first end of the current circuit switching unit is connected with a first output end of the rectification circuit through the impedance circuit, a second end of the current circuit switching unit is connected with a second output end of the rectification circuit, and a third end of the current circuit switching unit is connected with the second output end of the rectification circuit through the auxiliary source circuit. The driver also comprises a DC-DC control unit which is connected with the auxiliary source circuit and the DC-DC conversion circuit; and a switching control unit which is connected with the current circuit switching unit and is used for controlling the connection from the first end of the current circuit switching unit to the second end or the third end according to a preset rule, so as to reduce the power loss of the driver.

Description

technical field [0001] The present invention relates to the technical field of chopping and dimming, and more specifically, relates to an LED driver applied to the occasion of chopping and dimming. Background technique [0002] In the case of chopper dimming, the chopper voltage output by the phase angle dimmer is transmitted to the LED (Light Emitting Diode, light emitting diode) load after passing through the LED driver, and the LED can be changed by adjusting the conduction phase angle of the chopper voltage. The size of the driving current, and then change the brightness of the LED load. [0003] see figure 1 , the LED driver includes: a rectifier circuit 10 and a DC-DC conversion circuit 20 connected in turn between the phase angle dimmer and the LED load, and a series branch connected in parallel to the output side of the rectifier circuit 10 (including a series startup resistor R1 and the auxiliary source circuit 30), and the DC-DC control unit 40 connecting the aux...

AI Technical Summary

Problems solved by technology

[0004] It can be seen that after the DC-DC control unit 40 is started, the energy of the auxiliary source circuit 30 can be independently provided by the power supply VC, and the start-up resistor R1 does not need to exist at this time, and if R1 is still connected at the original position, unnecessary losses, resulting in lower overall efficiency of the LED driver

And if the loss caused by R1 is reduced by increasing the resistance value of the starting resistor R1, it will affect the starting speed of the DC-DC control unit 40

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