Linear high voltage LED driving circuit

Abstract

The invention provides a linear high voltage LED driving circuit comprising a rectifier bridge pile, two or more LED strings, driving switches matched with the LED strings, a current sampling circuit used for detecting current of each driving switch, and a constant current control circuit used for controlling each driving switch to conduct a resistant; the constant current control circuit and the driving switches are used for controlling the at least two LED strings to be partially or fully conducted for illumination according to the changes of the DC pulse voltage, so conducted illumination time of the LED string can be improved in one voltage pulse period, and power consumption of the driving switches is reduced, thus greatly improving LED driving efficiency.

Description

technical field [0001] The invention belongs to the technical field of light emitting diode (Light Emitting Diode, hereinafter referred to as: LED) lighting technology, and in particular relates to a linear high-voltage LED driving circuit. Background technique [0002] At present, the LED lighting power supply mainly adopts switching power supply, which has the advantages of high efficiency and small size. However, the switching power supply also has shortcomings that are difficult to overcome. The specific performance is: because the switching power supply uses electrolytic capacitors and transformers or inductors, the biggest disadvantage of electrolytic capacitors is short life and low reliability, and its service life can only reach 5000 at most. -8000 hours; and the service life of aluminum electrolytic capacitors will generally decrease by 10% for every 10°C increase in operating temperature, and the operating temperature of switching power supplies for LED lights is ...

AI Technical Summary

Problems solved by technology

In this application, only when the output voltage of the rectifier bridge stack is higher than the conduction voltage of the LED string, the LED string will emit light normally; and when the output voltage of the rectifier bridge stack is lower than the conduction voltage of the LED string, most of the power will be consumed On the constant current controller, and even if the output voltage of the rectifier bridge stack is higher than the conduction voltage of the LED string, a large part of the power consumption is on the constant current controller

Therefore, this traditional linear constant current LED driving method not only has low luminous efficiency, but also low power utilization.

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