Double-output high-efficiency LED light-modulating circuit
View Patent ↗The present invention relates to a double-output high-efficiency LED light-modulating circuit, comprising: a single-stage flyback power factor corrector, a DC/DC convertor, an LED module, and a light-modulating switch. In the present invention, it mainly utilizes the single-stage flyback power factor corrector for carrying out the purposes of reducing the components of an LED luminaire controlling circuit and increasing the circuit power conversion efficiency. Moreover, the double-output high-efficiency LED light-modulating circuit further includes a twin-bus light modulation framework, which can not only reduce the cross voltage of the power switch in back-end DC/DC convertor, but also process a high-frequency light modulation and a low-frequency light modulation to the LED luminaire. Therefore, because the cross voltage of the power switch has been reduced, a power switch with lower R ds can be used in the back-end DC/DC convertor for increasing switching speed and reducing switching losses.
1. A double-output high-efficiency LED light-modulating circuit, comprising:
a single-stage flyback power factor corrector, being coupled to an AC input voltage signal and capable of outputting a first LED voltage and a second LED voltage, so as to complete a twin-bus output; wherein the first LED voltage is slightly larger than the second LED voltage;
a DC/DC convertor, being coupled to the single-stage flyback power factor corrector for receiving the first LED voltage and the second LED voltage;
an LED module, being coupled to the DC/DC convertor and the single-stage flyback power factor corrector; and
a light-modulating switch, being coupled to the LED module and the single-stage flyback power factor corrector, so as to receive the first LED voltage and process a high-frequency light modulation and a low-frequency light modulation to the LED module.
2. The double-output high-efficiency LED light-modulating circuit of claim 1 , wherein the DC/DC convertor comprises:
an inductor, being coupled to the LED module;
a switch, being coupled to the inductor;
a switch resistor, being coupled to the switch; and
a first diode, being coupled between the LED module and the switch resistor and turned on when the high-frequency light modulation is processed.
3. The double-output high-efficiency LED light-modulating circuit of claim 2 , further comprising a second diode, which is coupled between the light-modulating switch and the inductor and turned on when the low-frequency light modulation is processed.
4. The double-output high-efficiency LED light-modulating circuit of claim 1 , wherein the LED module consists of a plurality of LED device.
5. The double-output high-efficiency LED light-modulating circuit of claim 1 , wherein the single-stage flyback power factor corrector is a power controlling integrated circuit (IC) with serial number of L6561.
6. The double-output high-efficiency LED light-modulating circuit of claim 1 , wherein the switch is a MOSFET.
7. The double-output high-efficiency LED light-modulating circuit of claim 1 , wherein the switch is a MOSFET.