Patent ID: 8736185

Claim:
A silicon-controlled rectifier (SCR) dimming circuit, comprising: a) an SCR element configured to generate a lack-phase AC voltage based on a sinusoidal AC supply; b) a rectifier bridge configured to generate a lack-phase DC voltage based on said lack-phase AC voltage; c) a conduction angle generator coupled to said rectifier bridge, wherein said conduction angle generator is configured to receive said lack-phase DC voltage, and to generate a controlling signal that is representative of a conduction angle of said SCR element; and d) a dimming signal generator coupled to said conduction angle generator and being configured to generate a dimming signal to regulate luminance of a light-emitting diode (LED) load in accordance with said lack-phase DC voltage, wherein said dimming signal generator is configured to receive said controlling signal, an adjustable signal, and a clamping voltage, wherein an amplitude of a dimming phase angle range is selected by a fixed signal determined by said clamping voltage, and wherein said dimming phase angle range is configured to be shifted by regulating said adjustable signal.