US 10,433,384 B2
LED driver with silicon controlled dimmer, apparatus and control method thereof
Qiukai Huang, Hangzhou (CN); Jianxin Wang, Hangzhou (CN); and Huiqiang Chen, Hangzhou (CN)
Assigned to Silergy Semiconductor Technology (Hangzhou) LTD, Hangzhou (CN)
Filed by Silergy Semiconductor Technology (Hangzhou) LTD, Hangzhou, ZheJiang Province (CN)
Filed on Apr. 18, 2018, as Appl. No. 15/955,853.
Claims priority of application No. 2017 1 0263893 (CN), filed on Apr. 21, 2017.
Prior Publication US 2018/0310376 A1, Oct. 25, 2018
Int. Cl. H05B 33/08 (2006.01)
CPC H05B 33/0845 (2013.01) [H05B 33/0809 (2013.01); H05B 33/0824 (2013.01)] 19 Claims
OG exemplary drawing
 
1. An apparatus, comprising:
a) a bleeder circuit coupled between a DC bus of a light-emitting diode (LED) driver having a silicon-controlled dimmer, and an LED driving sub-circuit having an LED load and a first transistor coupled in series;
b) a controller configured to control, when said silicon-controlled dimmer is off, said bleeder circuit to control a voltage of said DC bus that is generated across two output terminals of a rectifier bridge, wherein said rectifier bridge is coupled to said silicon-controlled dimmer, and said DC bus voltage is configured to provide a load driving voltage to said LED load; and
c) said bleeder circuit being configured to control said DC bus voltage to be approximate to a predetermined load driving voltage that is said load driving voltage when said silicon-controlled dimmer conducts at a maximum conduction angle.