Led drive circuit
First Claim
Patent Images
1. An LED drive circuit comprising:
- a plurality of LEDs coupled together in parallel, said LEDs configured to be powered by a battery;
a current source coupled to said LEDs, said current source providing a current signal level for driving said LEDs;
a current sensor circuit coupled to said current source and configured to provide a first indication signal in response to the current signal flowing in said LEDs;
a controller circuit coupled to said current sensor so as to receive said indication signal, said controller circuit further coupled to said current source so as to provide an appropriate voltage control signal to said current source so that the current drawn through said LEDs remains substantially at a desired level.
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Abstract
An LED drive circuit comprising a plurality of LEDs coupled together in parallel, the LEDs configured to be powered by a battery. A current source coupled to the LEDs provides a current signal level for driving the LEDs. A current sensor circuit is coupled to the current source and is configured to provide a first indication signal in response to the current signal flowing in the LEDs. A controller circuit is coupled to the current sensor so as to receive the indication signal. The controller circuit is further coupled to the current source so as to provide an appropriate control signal to the current source so that the current drawn through the LEDs remains substantially at a desired level.
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Citations
16 Claims
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1. An LED drive circuit comprising:
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a plurality of LEDs coupled together in parallel, said LEDs configured to be powered by a battery; a current source coupled to said LEDs, said current source providing a current signal level for driving said LEDs; a current sensor circuit coupled to said current source and configured to provide a first indication signal in response to the current signal flowing in said LEDs; a controller circuit coupled to said current sensor so as to receive said indication signal, said controller circuit further coupled to said current source so as to provide an appropriate voltage control signal to said current source so that the current drawn through said LEDs remains substantially at a desired level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for driving LEDs coupled in a plurality of parallel branches, each branch having a plurality of serially coupled LEDs, said method comprising the steps of:
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sensing the current signal drawn in at least one of said branches; generating an indication signal in response to the level of said current signal drawn in said at least one branch; generating a voltage control signal corresponding to said indication signal; and controlling the value of the current signal drawn in said branch in response to said voltage control signal. - View Dependent Claims (13, 14, 15, 16)
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Specification