Intelligent light degradation sensing LED traffic signal

• US 20050206529A1
• Filed: 03/30/2005
• Published: 09/22/2005
• Est. Priority Date: 01/23/2003
• Status: Active Grant

• Current Assignee: Current Lighting Solutions, LLC (f/k/a GE Lighting Solutions, LLC) (American Industrial Partners)
• Original Assignee: Lumination LLC
• Inventors: St.-Germain, Nicolas
• Granted Patent: US 7,425,798 B2
• Time in Patent Office: Days
• US Class Current: 340/815.450
• CPC Class Codes: B61L 2207/02 using light-emitting diodes [LEDs]
• CPC Class Codes: B61L 5/1881 Wiring diagrams for power supply, control or testing
• CPC Class Codes: G08G 1/095 Traffic lights
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/14 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/18 using temperature feedback
• CPC Class Codes: H05B 45/58 involving end of life detection of LEDs
• CPC Class Codes: H05B 47/20 Responsive to malfunctions or to light source life; for protection
• CPC Class Codes: Y02B 20/40 Control techniques providing energy savings, e.g. smart controller or presence detection

Abstract

The inventive signal incorporates an intelligent diagnosis module inside a light emitting diode (LED) signal, such as an LED traffic signal. The inventive signal can self-extinguish or send a signal through its communication port at the end of its useful life when the LEDs are no longer providing the required light output. Additionally, the inventive signal sends a signal to increase the current as the LEDs degrade to ensure the light output is above a threshold minimum.

Claims

1. An intelligent LED signal comprising:

a power supply,

an LED array powered by said power supply, and a

control module for controlling the signal wherein said control module is adapted to received LED data and to generate control signals.

2. The intelligent LED signal of claim 1 further comprising:

a receiver in communication with the control module, and said control module adapted to send LED data and control signals to the receiver.

3. The intelligent LED signal of claim 1 wherein the control module comrpsises s memory and a micro-controller.

4. The LED signal of claim 3 further comprising at least one LED data sensor, wherein said at least one LED data sensor is a voltage sensor, a current sensor, a thermal sensor, a photosensor or a timer.

5. The intelligent LED signal of claim 3 further comprising a voltage sensor, a current sensor, a thermal sensor, a photosensor and a timer, wherein the voltage sensor, the current sensor, the thermal sensor, the photosensor and the timer and adapted to measure LED data.

6. The intelligent LED signal of claim 5 wherein the temperature sensor measures the temperature on a power supply printed circuit board or on an LED printed circuit board.

7. The intelligent LED signal of claim 1 wherein the LED data comprises input voltage, temperature, output current, light output, average input voltage, average temperature, hours of operation of the LED array, and/or lamp ID.

8. The intelligent LED signal of claim 5 wherein the LED data comprises input voltage, temperature, output current, light output, average input voltage, average temperature, hours of operation of the LED array, and/or lamp ID.

9. The intelligent LED signal of claim 1 wherein the control signals comprise an End of Life signal, a current adjust signal, or a turn-off signal.

10. The intelligent LED signal of claim 8/wherein the control signals comprise an End of Life signal, a current adjust signal, or a turn-off signal.

11. The intelligent LED signal of claim 1 wherein the signal has a signal ID.

12. A method of controlling a LED signal comprising the steps of:

receiving LED data and

generating a control signal in response to the LED data,

wherein the LED data is voltage, ambient temperature, output current, light output, average input voltage, average ambient temperature;

hours of operation of the LED array, and/or lamp ID and the control signal is an End of Life signal, a current adjust signal, or a turn-off signal.

13. The method of controlling a LED signal of claim 12 further comprising the steps of measuring the ambient temperature using a temperature sample rate and calculating an average ambient temperature.

14. The method of controlling a LED signal of claim 12 further comprising the steps of measuring the input voltage using a voltage sample rate and calculating an average input voltage.

15. The method of controlling a LED signal of claim 12 further comprising the step of measuring the output current using a current sample rate.

16. The method of controlling a LED signal of claim 12 further comprising the step of measuring the light output using a light output sample rate.

17. The method of controlling a LED signal of claim 12 further comprising the step of timing the hours of operation.

18. The method of controlling a LED signal of claim 14 further comprising the steps of comparing the input voltage to a reference voltage and generating a turn-off signal if the input voltage is below the reference voltage.

19. The method of controlling a LED signal of claim 18 further comprising the step of turning off the signal in response to the turn-off signal.

20. The method of controlling a LED signal of claim 15 further comprising the step of measuring the light output using a light output sample rate.

21. The method of controlling a LED signal of claim 20 further comprising the steps comparing the light output to a light output minimum and comparing the current to a current maximum, and if the light output is below the light output minimum and the output current is below the current maximum generating a current adjust signal.

22. The method of controlling a LED signal of claim 21 further comprising the step of

increasing the output current in response to the current adjust signal.

23. The method of controlling a LED signal of claim 22 further comprising the steps of measuring the light output using a light output sample rate and timing the hours of operation.

24. The method of controlling a LED signal of claim 23 further comprising the steps of calculating a maximum number of hours wherein said maximum number of hours is proportional to the average ambient temperature, comparing the hours of operation to the maximum number of hours, comparing the light output to a light output minimum, and if the light output is below the light output minimum and hours of operation is greater than the maximum number of hours generating the End of Life signal.

25. The method of controlling a LED signal of claim 24 further comprising the steps communicating the End of Life signal to a receiver or turning-off the signal in response to the End of Life signal.

26. A method of controlling a LED signal comprising the steps of:

receiving LED data, said LED data is voltage, ambient temperature, output current, light output, average input voltage, average ambient temperature, hours of operation of the LED array, and/or lamp ID and the control signal is an End of Life signal, a current adjust signal, or a turn-off signal;

generating a control signal in response to the LED data;

measuring the ambient temperature using a temperature sample rate;

calculating an average ambient temperature;

measuring the input voltage using a voltage sample rate;

calculating an average input voltage;

measuring the output current using a current sample rate;

measuring the light output using a light output sample rate;

timing the hours of operation;

comparing the input voltage to a reference voltage and generating a turn-off signal if the input voltage is below the reference voltage;

comparing the light output to a light output minimum, comparing the current to a current maximum, and if the light output is below the light output minimum and the output current is below the current maximum generating a current adjust signal;

calculating a maximum number of hours, said maximum number of hours is proportional to the average ambient temperature, comparing the hours of operation to the maximum number of hours, comparing the light output to a light output minimum, and if the light output is below the light output minimum and hours of operation is greater than the maximum number of hours generating the End of Life signal.

27. The method of controlling a LED signal of claim 26 further comprising the step of turning off the signal in response to the turn-off signal.

28. The method of controlling a LED signal of claim 26 further comprising the step of increasing the output current in response to the current adjust signal.

29. The method of controlling a LED signal of claim 26 further comprising the steps communicating the End of Life signal to a receiver or turning-off the signal in response to the End of Life signal.

30. The method of controlling a LED signal of claim 26 further comprising the step of saving the LED data to memory.

31. The method of controlling a LED signal of claim 26 wherein

the current sample rate is predetermined and the light output sample rate is predetermined.

32. The method of controlling a LED signal of claim 26 wherein

an output current adjust and end of life calculation are performed every time the output current and light output are sampled.

33. The method of controlling a LED signal of claim 26 wherein

the current sample rate is predetermined,

the light output sample rate is predetermined and

an output current adjust and end of life calculation are performed every time the output current and light output are sampled.

34. The method of controlling a LED signal of claim 26 further comprising the step of communicating at least one LED data or at least one control signal to a receiver.

35. The method of controlling a LED signal of claim 26 wherein the voltage sample rate is at least one measurement every 1 ms and the temperature sample rate is at least one measurement every 100 ms.

36. The method of controlling a LED signal of claim 35 wherein

the current sample rate is every 168 hours of operation,

the light output sample rate is every 168 hours of operation and

an output current adjust and end of life calculation are performed every time the output current and light output are sampled.