SCR dimming circuit and method

摘要

The present invention relates to an SCR dimming circuit and method for regulating the luminance of an LED load. In one embodiment, an SCR dimming circuit can include: an SCR element that generates a lack-phase AC voltage based on a sinusoidal AC supply; a rectifier bridge that generates a lack-phase DC voltage based on the lack-phase AC voltage; a conduction angle generator that receives the lack-phase DC voltage, and generates a controlling signal representative of a conduction angle of the SCR element; and a dimming signal generator that generates a dimming signal to regulate luminance of the LED load, where the dimming signal generator receives the controlling signal, an adjustable signal, and a clamping voltage, an amplitude of a dimming phase angle range is selected by a fixed signal determined by the clamping voltage, and the dimming phase angle range may be shifted by regulating the adjustable signal.

主权项

1. 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 configured to receive said lack-phase DC voltage from said rectifier bridge, and to generate a controlling signal that represents a conduction angle of said SCR element, a clamping voltage, and an adjustment signal; and d) a dimming signal generator configured to generate a dimming signal in response to said controlling signal, said clamping voltage, and said adjustment signal, wherein said dimming signal is configured to regulate luminance of a light-emitting diode (LED) load in accordance with said lack-phase DC voltage.