Led driving circuit having scr dimmer, apparatus and control method thereof
AssigneeSilergy Semiconductor Technology (Hangzhou) LTD
InventorsJianxin Wang, Huiqiang Chen
Life of this patent
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Abstract
An apparatus can include: a bleeder circuit coupled to a DC bus of an LED driving circuit having an SCR dimmer; the bleeder circuit being configured to stabilize a voltage of the DC bus at a predetermined value by drawing a bleed current through a bleed path in a first mode, and to cut off the bleed path in a second mode; and a controller configured to control the bleeder circuit to be in the first mode before the SCR dimmer is turned on, and to switch to the second mode after the SCR dimmer is turned on, where the predetermined value is greater than zero.
Claims20
An apparatus, comprising:
- a) a bleeder circuit coupled to a DC bus of a light-emitting diode (LED) driving circuit having a silicon-controlled rectifier (SCR) dimmer;
- b) said bleeder circuit being configured to stabilize a voltage of said DC bus at a predetermined value by drawing a bleed current through a bleed path in a first mode, and to cut off said bleed path in a second mode;
- and
- c) a controller configured to control said bleeder circuit to be in said first mode before said SCR dimmer is turned on, and to switch to said second mode after said SCR dimmer is turned on, wherein said predetermined value is greater than zero.
A method of controlling a bleeder circuit coupled to a DC bus of a light-emitting diode (LED) driving circuit having a silicon-controlled rectifier (SCR) dimmer, the method comprising:
- a) stabilizing, by said bleeder circuit, a voltage of said DC bus at a predetermined value by drawing a bleed current through a bleed path in a first mode;
- b) cutting off, by said bleeder circuit, said bleed path in a second mode;
- and
- c) controlling said bleeder circuit to be in said first mode before said SCR dimmer is turned on, and to switch to said second mode after said SCR dimmer is turned on, wherein said predetermined value is greater than zero.
Dependencies are inferred from the claim text.