US 2014/0152187 A1 · CIRCUITS AND METHODS FOR DRIVING A LIGHT SOURCE

Abstract

A circuit includes a bridge circuit, a converter, and a controller. The bridge circuit receives power from first and second power lines of a switch and generates a rectified voltage. The switch is capable of operating in a first state in which the switch conducts power to the first power line but not the second power line, a second state in which the switch conducts power to the second power line but not the first power line, and a third state in which the switch conducts power to both the first and second power lines. The converter converts the rectified voltage to an output voltage to drive a light source, and controls a current through the light source according to a driving signal. The controller monitors the operation state of the switch and generates the driving signal based on the operation state to control brightness/dimming of the light source.

Claims22

Dependent claims

A circuit for driving a light source, said circuit comprising:

a bridge circuit coupled to a switch through a first power line and a second power line, and configured to receive power from said first and second power lines and generate a rectified voltage, wherein said switch operates in a plurality of operation states comprising a first state, a second state, and a third state, wherein in said first state said switch conducts power to said first power line but not said second power line, wherein in said second state said switch conducts power to said second power line but not said first power line, and wherein in said third state said switch conducts power to both said first and second power lines;
a converter coupled to said bridge circuit and configured to convert said rectified voltage to an output voltage to drive said light source, and control a current through said light source according to a driving signal;
and
a controller coupled to said converter and configured to monitor said operation state of said switch and generate said driving signal based on said operation state to control the light level of said light source.

1 more element

A controller for controlling power to a light emitting diode (LED) light source, said controller comprising:

a pair of detection pins coupled to a three-way switch through a first power line and a second power line, and configured to detect an operation state of said three-way switch comprising a first state, a second state, and a third state, wherein in said first state said three-way switch conducts power to said first power line but not said second power line, wherein in said second state said three-way switch conducts power to said second power line but not said first power line, wherein in said third state said three-way switch conducts power to both said first power line and said second power line, wherein a power converter receives power from said three-way switch and provides an output voltage to drive said LED light source;
and
an output pin configured to generate a driving signal according to said operation state to control said power converter, such that an average current through said LED light source is adjusted to a first level, a second level, and a third level when said three-way switch operates in said first, second, and third operation states, respectively.

A method for driving a light emitting diode (LED) light source, said method comprising:

receiving power from a three-way switch having a first power line and a second power line, wherein said three-way switch operates in a plurality of operation states comprising a first state, a second state, and a third state, wherein in said first state said switch conducts power to said first power line but not said second power line, wherein in said second state said switch conducts power to said second power line but not said first power line, and wherein in said third state said switch conducts power to both said first and second power lines;
providing an output voltage to drive said LED light source;
monitoring in which state said three-way switch operates;
and
generating a driving signal based on said operation state of said three-way switch to control a current through said LED light source.

2 more elements

Dependencies are inferred from the claim text.

Circuits and methods for driving a light source

Life of this patent

Circuits and methods for driving a light source

Life of this patent

Abstract

Claims22