US 2012/0256553 A1 · SCR DIMMING CIRCUIT AND METHOD

Abstract

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.

Claims20

Dependent claims

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.

2 more elements

A silicon-controlled rectifier (SCR) dimming method, the method comprising:

a) converting an external sinusoidal AC power supply to a lack-phase AC voltage;
b) converting said lack-phase AC voltage to a lack-phase DC voltage;
c) converting said lack-phase DC voltage to a controlling signal representing a conduction angle of an SCR element;
d) generating a dimming signal in response to said controlling signal, an adjustable signal, and a clamping voltage;
e) selecting an amplitude of a dimming phase angle range a fixed signal that is determined by said clamping voltage;
and
f) shifting said dimming phase angle range by regulating said adjustable signal.

4 more elements

Dependencies are inferred from the claim text.

Scr dimming circuit and method

Life of this patent

Scr dimming circuit and method

Life of this patent

Abstract

Claims20