Dimming control circuit, driving device and control method thereof
AssigneeShanghai Bright Power Semiconductor Co., Ltd.
InventorsWei-Jia Yu, Min-Min Fan
Life of this patent
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Abstract
A dimming control circuit, driving device and control method thereof, the dimming control circuit comprising a dimmer, a driving device coupled to the dimmer and controlling a load on the basis of a dimming level reference of the dimmer, and a bleeder supplying power to the dimmer, the driving device including a power switch coupled to the load, wherein a duty ratio of a driving voltage on the power switch is adjusted in accordance with the dimming level reference to control an operating current of the load.
Claims19
A driving device utilized in a dimming control circuit for driving a load, the driving device configured to receive an output of a rectifier, the rectifier configured to receive an AC power and to output a rectified DC output voltage to the load, wherein the driving device comprises:
- a power switch serially coupled to the load, configured to regulate a current flowing through the load;
- and
- a power switch control module, configured to generate a pulse width modulation signal to control the power switch on and off, wherein the pulse width modulation signal turns to an on-state state according to a conducting signal, the conducting signal being configured to indicate the rectified output voltage reaching a first reference, and wherein a duty ratio of the pulse width modulation signal is adjusted in accordance with an error between a sensed signal indicating a current flowing through the load and a dimming level reference.
A dimming control method used for a dimming control circuit, the dimming control circuit comprising a dimmer, a rectifier, a driving device and a bleeder, the rectifier being coupled to the dimmer and configured to receive an AC power and to output a rectified DC output voltage to a load, the driving device comprising a power switch coupled to the load and a pulse width modulation signal generator, the power switch controlling the load on the basis of a dimming signal, the bleeder supplying power to the dimmer, wherein the method comprises the following steps:
- receiving a conduction signal based on the rectified DC output voltage and a off signal based on the dimming signal by the pulse width modulation signal generator;
- and
- outputting a pulse width modulation signal to the power switch on the basis of the conduction signal and the off signal, wherein a duty ratio of the pulse width modulation signal is adjusted in accordance with an error between a sensed signal indicating a current flowing through the load and a dimming level reference.
Dependencies are inferred from the claim text.