Dimming circuit for linear high voltage led driver

Abstract

The invention provides a light dimming circuit for a linear high-voltage LED driver. The light dimming circuit comprises a bridge rectifier, at least two sections of LED strings, a driving control IC, a driving switch, a PWM control switch and a PWM signal input end, wherein positive electrodes and negative electrodes of the LED strings are in serial connection in an end-to-end mode. After the PWM control switch receives PWM signals, the time proportion of on-off time of the driving switch is controlled to adjust the time ratio between luminous time and nonluminous time of the LED strings to finally achieve the purpose of dimming light. The light dimming circuit achieves the light dimming function of LED lighting lamps by using the linear high-voltage LED driving scheme.

Description

technical field [0001] The invention belongs to the technical field of LED lighting, and in particular relates to a dimming circuit suitable for a linear high-voltage LED driver. Background technique [0002] Now some companies have introduced a linear high-voltage LED driver to drive LED lamps. It needs to connect no less than two LED strings in series or a combination of series and parallel LED strings into the circuit in sequence, and then the rectified pulsation The voltage is applied to the LED string, and finally the voltage input to each segment of the LED string is measured by the drive control chip. After the input voltage reaches a certain value, the driver chip drives the first segment of the LED string and constant current at a lower current value; After reaching a higher voltage, drive the second segment of the LED string and keep the constant current at a higher current; finally wait until the voltage is higher, then switch on the third segment of the LED strin...

AI Technical Summary

Problems solved by technology

However, compared with LED lamps driven by switching power supplies, there is still room for improvement in the invention of dimming.

[0003] At present, the dimming control of LED lamps using linear high-voltage LED drivers generally uses silicon controlled silicon dimmers, which not only have low efficiency but also poor dimming effects.

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