LED lighting system
First Claim
1. An LED lighting system emitting light having an overall intensity, said system comprising:
- a plurality of LEDs each having a maximum current capacity;
at least one constant-current driver for supplying a substantially constant current to said plurality of LEDs, said at least one constant-current driver being set to supply said constant current at a level less than said maximum current capacity, wherein said level of constant current to each of said plurality of LEDs is less than approximately 50% of said maximum current capacity for said LEDs; and
whereby luminous efficiency of said LED lighting system is increased without decreasing said overall intensity of said light.
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Accused Products
Abstract
A method for optimizing an LED lighting system cost includes steps of determining LED costs, power source costs, and total costs associated with a plurality of LED quantities, and identifying a lowest total cost as an optimal cost. A LED lighting system includes an LED operated by a constant-current driver at less than its maximum current capacity. A programmable controller including a feedback routine is used to compensate for intensity drift as an LED ages. Other embodiments of LED lighting systems include multiple LEDs producing light having various spectrums to optimize the lighting system efficiency and the effectiveness. A charge controller including an MPPT routine is advantageously employed with a LED lighting system powered by a limited-capacity power source.
77 Citations
18 Claims
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1. An LED lighting system emitting light having an overall intensity, said system comprising:
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a plurality of LEDs each having a maximum current capacity; at least one constant-current driver for supplying a substantially constant current to said plurality of LEDs, said at least one constant-current driver being set to supply said constant current at a level less than said maximum current capacity, wherein said level of constant current to each of said plurality of LEDs is less than approximately 50% of said maximum current capacity for said LEDs; and whereby luminous efficiency of said LED lighting system is increased without decreasing said overall intensity of said light. - View Dependent Claims (14, 15)
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2. An LED lighting system producing light having an overall spectrum, said system comprising:
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a first LED producing light having a first spectrum and an adjustable first intensity; a second LED producing light having a second spectrum and an adjustable second intensity; a programmable controller for independently adjusting said first and second intensities; and a light detection means for detecting an ambient light condition; and a battery for supplying power to said LED lighting system; and a charge detection means for determining a state of charge of said battery and communicating said state of charge to said programmable controller; wherein said programmable controller includes a spectrum adjustment routine for adjusting at least one of said first and second adjustable intensities to adjust said overall spectrum in response to said ambient light condition and wherein said programmable controller performs said spectrum adjustment routine when said state of charge falls below a pre-determined threshold. - View Dependent Claims (3)
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4. An LED lighting system comprising:
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at least one LED having a maximum current capacity; and at least one constant-current driver for supplying a substantially constant current to said at least one LED, said at least one constant-current driver being set to supply said constant current at a level less than said maximum current capacity, wherein said level of constant current to each of said at least one LED is less than approximately 50% of said maximum current capacity for said LED; and whereby luminous efficiency of said LED lighting system is increased, wherein said maximum luminous intensity of said system is increased by adding additional LEDs, each of said additional LEDs operating at less than approximately 50% of said maximum current capacity for said additional LEDs. - View Dependent Claims (5, 6)
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7. An LED lighting system comprising:
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a first LED producing light having a first spectrum substantially corresponding to one of a peak scotopic and a peak photopic sensitivity of a human eye; and a second LED producing light having a second spectrum; and wherein said system reduces power demands by providing either said first spectrum or said second spectrum depending upon which is most effective for vision in either scotopic or photopic ambient conditions. - View Dependent Claims (8, 9, 10)
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11. An LED lighting system producing light having an overall spectrum, said system comprising:
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a first LED producing light having a first spectrum and an adjustable first intensity; a second LED producing light having a second spectrum and an adjustable second intensity; a programmable controller for independently adjusting said first and second intensities; a first constant-current driver for supplying a first constant current to said first LED in response to a first PWM control signal; and a second constant-current driver for supplying a second constant current to said second LED in response to a second PWM control signal; wherein said programmable controller generates said first and second PWM control signals and supplies said first and second PWM control signals to said first and second constant-current drivers, respectively, and said programmable controller independently adjusts said first and second intensities by independently adjusting said first and second PWM control signals; and wherein said programmable controller actively and continuously reduces energy demands of said LEDs by shifting said overall spectrum to a most efficient spectrum of one of said first and second spectrums for a given ambient condition. - View Dependent Claims (12, 13, 16, 17, 18)
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Specification