US Patent No. 10,143,051

BLEEDER CIRCUIT AND CONTROL METHOD THEREOF, AND LED CONTROL CIRCUIT


Patent No. 10,143,051
Issue Date November 27, 2018
Title Bleeder Circuit And Control Method Thereof, And Led Control Circuit
Inventorship Guoqiang Liu, Zhejiang (CN)
Pitleong Wong, Zhejiang (CN)
Yuancheng Ren, Zhejiang (CN)
Xunwei Zhou, Zhejiang (CN)
Assignee JOULWATT TECHNOLOGY (HANGZHOU) CO., LTD., Hangzhou, Zhejiang (CN)

Claim of US Patent No. 10,143,051

1. A bleeder circuit, comprising:a) a bleeder module, having alternating current (AC) input through a triode alternating current (TRIAC) dimmer and a rectifying bridge to get input voltage to provide a load with power supply through a driving circuit, two ends of the bleeder module being connected to high and low potential terminals of an input voltage detecting circuit respectively; and
b) a bleeder control circuit, connected to a control terminal of the bleeder module; directly or indirectly detecting cross-zero point of input voltage; after the cross-zero point of input voltage is delayed by a second time, the bleeder module works to generate bleeder current, and a time between turn-on time of the TRIAC dimmer and a time that a driving circuit input current achieves a predetermined value is a first time;
wherein, when the first time is greater than a reference time, the second time is prolonged; and when the first time is smaller than the reference time, the second time is reduced, such that the first time is close to the reference time;
wherein the bleeder control circuit comprises an input voltage detecting circuit, an input current detecting circuit of a driving circuit, and a logic circuit; the logic circuit is connected to a control terminal of the bleeder module, and the input voltage detection circuit samples the input voltage; when the input voltage sample signal achieves a threshold voltage, after being delayed for a second time, the bleeder module is controlled by the logic circuit to generate bleeder current; the input current detecting circuit of the driving circuit detects the input current of the driving circuit, and when the sample current achieves a threshold current indicating a predetermined current, the bleeder current is controlled by the logic circuit to be zero; comparing the first time with the reference time, and adjusting the second time correspondingly according to the comparison result.