led drive circuit

Abstract

The present invention provides an LED driving circuit. By making the power converter provide a constant driving current to the LED lamp string group, the toning control circuit generates a set of switches according to a set of toning pulse width signals generated by the pulse width signal generator. control signal, the switch control signal controls the switch state of the control switch group connected in series with the LED light string group, thereby adjusting the proportion of the current of each LED light string in the LED light string group to the driving current, thereby adjusting The color temperature of the LED light string group. In addition, the dimming pulse width signal output by the pulse width signal generator can also enable the constant current control circuit to adjust the magnitude of the driving current to realize the dimming function. Therefore, the LED drive circuit does not need to be equipped with an independent constant current drive circuit and constant current control circuit for dimming and color adjustment for each LED light string. The circuit structure is relatively simple and easy to integrate, and the peripheral components used are relatively small. Small volume, low production cost.

Description

technical field [0001] The invention relates to the field of electronic technology, in particular to an LED driving circuit. 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. refer to figure 1 , shows an LED driving circuit using the prior art. In this implementation, the AC voltage Vac outputs the voltage Vin after passing through the rectification and filtering circuit 01, and the power converter 02 receiv...

AI Technical Summary

Problems solved by technology

[0004] It can be seen from the above that the implementation of this LED drive circuit in the prior art requires an independent constant current drive circuit to drive the LED light strings of the corresponding color, and each constant current drive circuit needs to be equipped with a constant current drive control circuit. Such an implementation method, The circuit structure is too complex

In addition, since the constant current drive circuit is usually built with many devices such as energy storage components, the realization of this dimming and color adjustment circuit requires many electronic components, the production cost is high, and the volume of the system is very large. bulky, not conducive to integration

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