A step-down constant current LED driving circuit, driving device and lighting system

Abstract

The invention is applicable to the field of lighting, and provides a voltage-reduction constant-current LED (Light Emitting Diode) driving circuit, a driving device and a lighting system. The circuit comprises a driving control unit, a driving current regulation unit, a chopping unit, a voltage reduction unit and a constant current keeping unit, wherein the driving control unit is used for generating a driving control signal after power-on; the driving current regulation unit is used for generating a frequency control signal to regulate frequency of the driving control signal to realize driving current regulation; the chopping unit is used for performing chopping on power supply current according to the driving control signal and generating a chopping signal; the voltage reduction unit is used for performing voltage reduction and voltage stabilization on the chopping signal and generating a direct current voltage reduction driving signal to drive an LED in a voltage reduction manner; and the constant current keeping unit is used for controlling current stabilization of the LED through a voltage reference source. The circuit replaces a high-cost driving chip or a high-cost single-chip microcomputer with a low-cost non-special chip to generate a square wave pulse signal to perform the chopping and the voltage reduction on the power supply current to realize LED driving; constant driving current is kept through the voltage reference source; and the circuit is simple in scheme and low in cost.

Description

technical field [0001] The invention belongs to the field of lighting, and in particular relates to a step-down constant current LED driving circuit, a driving device and a lighting system. Background technique [0002] With the rapid development of the fourth-generation lighting technology, in recent years, more and more light-emitting diodes (Light Emitting Diode, LED) are used as light sources in lighting systems such as torches or portable searchlights. For the driving of LEDs, most of them currently use dedicated The LED driver chip or programmable single-chip microcomputer generates a pulse width modulation (Pulse WidthModulation, PWM) signal to drive the MOS tube or triode to chop the battery current, and then forms a DC step-down drive LED through the BUCK (step-down) circuit, and Through the feedback circuit, the feedback signal is output to the dedicated LED driver chip or programmable single-chip microcomputer to control the PWM pulse width, and then control the c...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the embodiment of the present invention is to provide a step-down constant current LED drive circuit, aiming to solve the problem of high production and maintenance costs of the current LED drive circuit

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