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US 6,556,463 B1Granted
Reduced electronic noise power supply to discharge lamps, especially for motor vehicle headlights
AssigneeValeo Vision
InventorsDaniel La Dret, Jean-Marc Nicolaï
Life of this patent
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Abstract
A discharge lamp for a motor vehicle headlight is fed through a power supply device which includes a dc/ac converter. The power supplied to the dc/ac converter is modulated over time, preferably in a pseudo-random sequence. A power supply device adapted to perform this method is also described.
Claims7
A power supply adapted to provide alternating current power to a lamp, the power supply comprising:
- a dc/dc converter adapted to provide a direct current power, the dc/dc converter having a transformer and a dc/dc interrupter configured to control power supply to the transformer;
- a dc/ac converter having a second interrupter controlled by a clock circuit adapted to receive the direct current power from the dc/dc converter and to output an alternating current power;
- and
- a regulator configured to control the dc/dc interruptor to modulate the direct current power supplied to the dc/ac converter so that a spectrum of current flowing in the lamp is widened without modifying control of the second interruptor of the dc/ac converter.
1 more element
A method comprising:
- providing a power supply and a discharge lamp associated with the power supply, the power supply comprising (1) a dc/dc converter with a transformer having an input and an output, and (2) a dc/ac current converter connected to the transformer output;
- and
- regulating the dc/dc converter to modulate the transformer output supplied to the dc/ac current converter to widen the spectrum of current flowing into the lamp without modifying control of the dc/ac converter.
A method comprising:
- providing a power supply and a discharge lamp associated with the power supply, the power supply comprising (1) a dc/dc converter with a transformer having an input and an output, and (2) a dc/ac current converter connected to the transformer output;
- and
- adding a modulated differential power to the transformer output supplied to the dc/ac current converter to widen the spectrum of current flowing into the lamp without modifying control of the dc/ac converter.
A power supply for supplying AC voltage to a lamp, said power supply comprising
- a dc voltage input;
- a dc/dc converter associated with the dc voltage input, said dc/dc converter having a voltage output;
- a dc/ac converter adapted to receive the dc voltage output and to provide ac power to the lamp;
- and
- means for widening the spectrum of current flowing into the lamp without modifying control of the dc/ac converter.
2 more elements
Dependencies are inferred from the claim text.