LOAD CONTROL DEVICE FOR A LIGHT-EMITTING DIODE LIGHT SOURCE
First Claim
1. A load control device for controlling an intensity of a lighting load, the load control device comprising:
- a power converter circuit operable to receive a rectified AC voltage and to generate a DC bus voltage;
a load regulation circuit operable to receive the DC bus voltage and to control a magnitude of a load current conducted through the lighting load; and
a control circuit operatively coupled to the load regulation circuit for pulse width modulating or pulse frequency modulating the load current to control the intensity of the lighting load to a target intensity;
wherein the control circuit is configured to control the intensity of the lighting load by pulse width modulating the load current when the target intensity is above a predetermined threshold and control the intensity of the lighting load by pulse frequency modulating the load current when the target intensity is below the predetermined threshold.
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Accused Products
Abstract
A load control device for controlling the intensity of a lighting load, such as a light-emitting diode (LED) light source, may include a power converter circuit operable to receive a rectified AC voltage and to generate a DC bus voltage, a load regulation circuit operable to receive the bus voltage and to control the magnitude of a load current conducted through the lighting load, and a control circuit operatively coupled to the load regulation circuit for pulse width modulating or pulse frequency modulating the load current to control the intensity of the lighting load to a target intensity. The control circuit may control the intensity of the lighting load by pulse width modulating the load current when the target intensity is above a predetermined threshold and control the intensity of the lighting load by pulse frequency modulating the load current when the target intensity is below the predetermined threshold.
128 Citations
20 Claims
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1. A load control device for controlling an intensity of a lighting load, the load control device comprising:
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a power converter circuit operable to receive a rectified AC voltage and to generate a DC bus voltage; a load regulation circuit operable to receive the DC bus voltage and to control a magnitude of a load current conducted through the lighting load; and a control circuit operatively coupled to the load regulation circuit for pulse width modulating or pulse frequency modulating the load current to control the intensity of the lighting load to a target intensity; wherein the control circuit is configured to control the intensity of the lighting load by pulse width modulating the load current when the target intensity is above a predetermined threshold and control the intensity of the lighting load by pulse frequency modulating the load current when the target intensity is below the predetermined threshold. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 17, 18)
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10. A load control device for controlling an intensity of a lighting load, the load control device comprising:
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a power converter circuit operable to receive a rectified AC voltage and to generate a DC bus voltage; a load regulation circuit operable to receive the DC bus voltage and to control a magnitude of a load current conducted through the lighting load; and a control circuit operatively coupled to the load regulation circuit for pulse width modulating or pulse frequency modulating the load current to control the intensity of the lighting load to a target intensity; wherein the control circuit is configured to control the intensity of the lighting load by pulse width modulating the load current when the target intensity is within a first intensity range and control the intensity of the lighting load by pulse frequency modulating the load current when the target intensity is within a second intensity range; and wherein the control circuit is configured to receive a command and control the intensity of the lighting load below the first intensity range and below the second intensity range to off. - View Dependent Claims (11, 12)
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13. A method for controlling an intensity of a lighting load, the method comprising:
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receiving a rectified AC voltage; generating a DC bus voltage from the rectified AC voltage; controlling a magnitude of a load current conducted through the lighting load using the DC bus voltage; and controlling the intensity of the lighting load to a target intensity, wherein the intensity of the lighting load is controlled by pulse width modulating the load current when the target intensity is above a predetermined threshold and by pulse frequency modulating the load current when the target intensity is below the predetermined threshold. - View Dependent Claims (14, 15, 16, 19, 20)
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Specification