US 12,484,121 B2
Lighting circuit and control method thereof
Wanyue He, Hangzhou (CN); and Guoqiang Liu, Hangzhou (CN)
Assigned to Joulwatt Technology Co., Ltd., Hangzhou (CN)
Filed by Joulwatt Technology Co., Ltd., Hangzhou (CN)
Filed on Jul. 24, 2024, as Appl. No. 18/782,097.
Claims priority of application No. 202311349780.6 (CN), filed on Oct. 17, 2023.
Prior Publication US 2025/0126689 A1, Apr. 17, 2025
Int. Cl. H05B 45/10 (2020.01); H05B 45/3575 (2020.01); H05B 45/37 (2020.01); H05B 45/44 (2020.01)
CPC H05B 45/10 (2020.01) [H05B 45/3575 (2020.01); H05B 45/37 (2020.01); H05B 45/44 (2020.01)] 15 Claims
OG exemplary drawing
 
1. A lighting circuit, comprising a triac dimmer and a rectifier circuit, wherein the triac dimmer is connected between an alternating current (AC) input power supply and the rectifier circuit, the rectifier circuit is configured to output a bus voltage after phase cutting, and the lighting circuit further comprises:
a turn-on angle detection circuit configured to detect a turn-on state of the triac dimmer, and output a first detection signal, wherein the first detection signal represents a relationship between a turn-on angle of the triac dimmer and a first angle; and
a bleeder circuit connected to the rectifier circuit and configured to receive a sampling signal representing a current of a light-emitting diode (LED) load and the first detection signal, and control a turn-on state of the bleeder circuit based on the first detection signal and the sampling signal; wherein
when the first detection signal represents that the turn-on angle is less than or equal to the first angle, and turn-on time of the triac dimmer reaches first time, when the sampling signal is greater than or equal to a first threshold, the bleeder circuit keeps on; or when the sampling signal is less than the first threshold, the bleeder circuit is turned off.