LED color temperature adjusting circuit capable of effectively preventing current overshoot

Abstract

The invention relates to an LED color temperature adjusting circuit capable of effectively preventing current overshoot, which is respectively connected with a cold color temperature LED and a warm color temperature LED, and comprises an LED constant current driving circuit, a dimming control singlechip, a cold color temperature driving MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) and a warm color temperature driving MOSFET, wherein the LED constant current driving circuit is respectively connected with the dimming control single chip microcomputer, the cold color temperature driving MOSFET and the warm color temperature driving MOSFET, the cold color temperature driving MOSFET is connected with the cold color temperature LED, the warm color temperature driving MOSFET is connected with the warm color temperature LED. The adjusting circuit further comprises a color temperature adjusting driving circuit, and the color temperature adjusting driving circuit is respectively connected with the dimming control singlechip, the cold color temperature driving MOSFET and the warm color temperature driving MOSFET. Compared with the prior art, the adjusting circuit has the advantages of reducing the cost, ensuring the reliability and the like.

Description

Technical field [0001] The present invention relates to an LED color temperature adjusting circuit, particularly relates to an efficient prevent current overshoot LED color temperature adjustment circuit. Background technique [0002] Mature existing mainstream color temperature adjuster LED driver products, such as circuit block figure 1 Shown, respectively a set of DC / DC LED drive the cold and warm color temperature LED color temperature, such a temperature adjustment circuit good results, to be reliable, but the high cost of the drive circuit DCDC. [0003] Another color temperature adjusting a low cost LED driver products, such as circuit block figure 2 Shown, respectively driving the conventional simple cold color temperature prior dimming control signal PWM microcontroller 201 drives two MOSFET202 warm color temperature and the drive current flows to the LED MOSFET203 switches constant current drive circuit 200 prior cold color temperature LED 204 two or two conventional ...

AI Technical Summary

Problems solved by technology

Therefore, if the two MOSFETs for color temperature adjustment do not have overlapping conduction time, the LED constant current drive circuit will be opened when the two MOSFETs are switched, resulting in an increase in the output voltage, and an instantaneous current will be caused when the other MOSFET is switched on. Excessively large risk of damaging the LED and MOSFET

like image 3 MOSFET switching timing, will cause LED and MOSFET damage

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