LED lighting system

• US 20060149607A1
• Filed: 12/30/2005
• Published: 07/06/2006
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Solarone Solutions, Inc. (Reden Solar SAS)
• Original Assignee: Solarone Solutions, LLC (Reden Solar SAS)
• Inventors: Azzam, Moneer, Fox, Martin, Karlicek, Robert F. Jr., Bernier, Joseph, Sayers, Graham, Lemons, Thomas M.
• Granted Patent: US 7,863,829 B2
• Time in Patent Office: Days
• US Class Current: 705/7
• CPC Class Codes: G06Q 50/06 Energy or water supply

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.

Claims

1. A method for optimizing an LED lighting system cost, said method comprising steps of:

determining a first LED cost and a second LED cost, respectively associated with selecting a first LED quantity and a second LED quantity, said second LED quantity exceeding said first LED quantity;

determining a first power source cost and second power source cost, respectively associated with supplying a first power to said first LED quantity and a second power to said second LED quantity;

determining a first total cost and a second total cost including, respectively, said first LED cost and said first power source cost, and said second LED cost and said second power source cost; and

identifying as an optimal quantity of LEDs said first LED quantity if said first total cost is lower than said second total cost, and said second LED quantity if said second total cost is lower than said first total cost;

wherein a first luminous efficiency associated with operating said first LED quantity and a second luminous efficiency associated with operating said second LED quantity are considered in determining at least one of said first and second LED costs, said first and second power source costs, and said first and second total costs.

2. The method of claim 1, wherein determining said first and second power source costs includes determining respective first and second power storage capacity costs and respective first and second power generation costs.

3. The method of claim 1, wherein said first and second power source costs are associated with a solar power system, and determining said first and second power source costs includes determining respective first and second photovoltaic panel costs and respective first and second battery costs.

4. The method of claim 1, wherein determining said first and second LED costs includes determining respective first and second costs for associated circuitry.

5. The method of claim 1, wherein said first LED quantity is at least two and said second LED quantity is a multiple of said first LED quantity.

6. The method of claim 1, wherein said first and second LED costs, said first and second power source costs, and said first and second total costs are expressed as costs per lumen.

7. The method of claim 1, wherein a plurality of additional LED costs, power source costs, and total costs associated with each of a plurality of additional LED quantities are further determined and compared to identify said optimal quantity of LEDs.

8. A LED lighting system comprising:

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;

whereby luminous efficiency of said LED lighting system is increased.

9. The system of claim 8, further comprising a programmable controller including a PWM signal generator for generating a PWM control signal and supplying said PWM control signal to said constant-current driver, wherein said constant-current driver supplies said substantially constant current in response to said PWM control signal.

10. The system of claim 8, wherein said constant-current driver is set to supply said substantially constant current at less than approximately 50% of said maximum current capacity.

11. The system of claim 8, wherein said constant-current driver is set to supply said constant current at less than approximately 35% of said maximum current capacity.

12. A LED lighting system comprising:

at least one LED having an intensity;

a feedback means for detecting said intensity;

a programmable controller for adjusting said intensity, said programmable controller including an intensity compensation routine for adjusting said intensity to compensate an intensity drift of said LED, based on said intensity as detected by said feedback means.

whereby said programmable controller compensates for said intensity drift in said LED as said LED ages.

13. A LED lighting system producing light having an overall spectrum, said system comprising:

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.

14. The system of claim 13, further comprising:

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.

15. The system of claim 13, further comprising:

a light detection means for detecting an ambient light condition;

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.

16. The system of claim 15, wherein said programmable controller performs said spectrum adjustment routine to adjust said overall spectrum to substantially correspond to at least one of a peak scotopic and a peak photopic condition of a human eye.

17. The system of claim 15, further comprising:

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 performs said spectrum adjustment routine when said state of charge falls below a pre-determined threshold.

18. The system of claim 13, wherein said first LED has a greater luminous efficiency than said second LED, and said programmable controller includes an efficiency enhancement routine for increasing an overall efficiency of said LED lighting system by operating said first LED at a higher intensity relative to said second LED.

19. The system of claim 18, further comprising:

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 controls performs said efficiency enhancement routine when said state of charge falls below a pre-determined threshold.

20. The system of claim 13, further comprising:

a feedback means for independently detecting an actual first intensity and an actual second intensity of said first and second LEDs, respectively, and communicating said actual first and second intensities to said programmable controller;

wherein said programmable controller includes a feedback routine for using said actual first and second intensities as feedback for adjusting said adjustable first and second intensities.

21. The system of claim 20, wherein said feedback means is a wide-range photodetector and said feedback routine enables said wide-range photodetector to independently detect said actual first and second intensities by controlling said first and second LEDs to conduct a first isolation period when only said first LED is operated and a second isolation period when only said second LED is operated.

22. The system of claim 21, wherein said programmable controller rapidly conducts said first and second isolation periods so as to make said first and second isolation periods visually undetectable.

23. The system of claim 14, further comprising:

a wide-range photodetector for detecting an actual first intensity and an actual second intensity of said first and second LEDs, respectively;

wherein said programmable controller includes a feedback routine for coordinating said first and second PWM control signals such that a first isolation period periodically occurs when only said first LED is operated and a second isolation period periodically occurs when only said second LED is operated, so as to enable said wide-range photodetector to independently detect said actual first and second intensities.

24. The system of claim 13, wherein said programmable controller includes an information routine for adjusting at least one of said first and second intensities to convey information to a user of said system by said system.

25. An LED lighting system comprising:

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.

26. The LED lighting system of claim 25, wherein said first spectrum substantially corresponds to said peak scotopic sensitivity and said second spectrum includes wavelengths substantially corresponding to said peak photopic sensitivity.

27. The LED lighting system of claim 26, wherein said first LED is a cyan LED and said second LED is a PC LED.

28. The LED lighting system of claim 25, further comprising a third LED and a fourth LED, and wherein said first LED is a cyan LED, said second LED is a blue LED, said third LED is a green LED, and said fourth LED is a red LED.

29. A LED lighting system comprising:

at least one LED assembly including an LED and a current adjustment means for said LED, said LED assembly adapted for optical communications;

a programmable controller for controlling said at least one LED assembly and adapted for optical communications; and

a first fiber optic line for carrying optical communications between said programmable controller and said at least one LED assembly.

30. An LED lighting system comprising:

a least one LED;

a battery;

a limited-capacity power source for charging said battery;

a charge controller including an MPPT routine for maximizing the rate at which said power source charge said battery in sub-optimal charging conditions.

31. The LED lighting system of claim 30, wherein said limited-capacity power source includes a PV panel.