LED (Light Emitting Diode) drive circuit capable of adjusting light and color temperature

Abstract

The invention relates to an LED (Light Emitting Diode) drive circuit capable of adjusting light and color temperature. The LED drive circuit is adopted for driving an LED lighting device which consists of N paths of LED string lights, wherein N is more than or equal to 2. The LED drive circuit comprises a constant current generating circuit, a buffer circuit, a selection circuit and a control circuit. According to the light adjusting and color temperature adjusting demand of the LED lighting device, a corresponding control signal is generated by the control circuit to control the states of the constant current generating circuit and the selection circuit. A direct current input voltage and the control signal are received by the constant current generating circuit, so that a constant output current is generated to drive the LED lighting device. The buffer circuit is connected to the output end of the constant current generating circuit, so that the output voltage which is output by the constant current generating circuit is limited. The selection circuit is connected with N paths of the LED string lights, so that the corresponding LED string light is selected according to the control signal and driven by the output current.

Description

technical field [0001] The invention relates to the lighting field, in particular to an LED drive circuit with adjustable light and adjustable color temperature. Background technique [0002] As a new type of lighting tool, LED lighting has the advantages of high light efficiency, long life, and environmental protection, so it is more and more widely used in various lighting fields. There are two ways of LED dimming: DC dimming and PWM dimming. Since PWM dimming has the advantages of constant light color and better stability at low brightness, it is widely adopted by those skilled in the art. [0003] For some special light source environments, not only the brightness of the LED lamps needs to be adjusted, but also the color temperature of the LED lamps needs to be adjusted. In the prior art, LED lamps of different colors are usually packaged in a single packaging structure as an independent LED lamp, and different color temperatures are obtained by combining LED lamps of ...

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Problems solved by technology

[0011] In view of this, the purpose of the present invention is to provide a new type of LED drive circuit with adjustable light and adjustable color temperature to solve the problems in the prior art that the circuit structure is too complicated, the number of components is too large, and the utilization rate is not high.

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