LUMINAIRE DRIVE CIRCUIT
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Accused Products
Abstract
A luminaire drive circuit (1) comprises an AC to DC power supply (2) delivering DC power to rails (3), and a plurality of LED drive circuits (4) connected across the rails to receive DC power. Each LED drive circuit (4) comprises a plurality of LEDs (7) in series and a voltage and current controller (6) for controlling current through the LEDs and a voltage across the LEDs which is less than the voltage across the rails. In one example, each LED circuit (4) has a dedicated sensor (52) to detect proximity of an illuminated object. This allows control of illumination intensity both for energy efficiency and visual effect. The proximity sensor may be simply a photodiode (52) mounted to detect extent of light reflected from the objects (FIG. 5), thus avoiding need for a self-contained proximity sensor such as one of the ultrasonic type.
39 Citations
39 Claims
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1-20. -20. (canceled)
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21. A luminaire drive circuit comprising:
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DC power rails, and a plurality of LED drive circuits connected across the rails to receive DC power, each LED drive circuit comprising a plurality of LEDs in series and comprising a voltage and current controller for controlling current through the LEDs and voltage across the LEDs which is less than the voltage across the rails; and wherein a fixed voltage plus the total LED forward voltage is less than a worst case minimum supply voltage. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38)
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39. A luminaire comprising a plurality of light emitting diodes mounted on a circuit and a drive circuit comprising:
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DC power rails, and a plurality of LED drive circuits connected across the rails to receive DC power, each LED drive circuit comprising a plurality of LEDs in series and comprising a voltage and current controller for controlling current through the LEDs and voltage across the LEDs which is less than the voltage across the rails; and wherein a fixed voltage plus the total LED forward voltage is less than a worst case minimum supply voltage.
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Specification