Lighting control circuit including LED for detecting exposure to radiation

• US 6,617,560 B2
• Filed: 05/30/2001
• Issued: 09/09/2003
• Est. Priority Date: 05/30/2001
• Status: Active Grant

• Current Assignee: The Watt Stopper Incorporated (Legrand SA)
• Original Assignee: The Watt Stopper Incorporated (Legrand SA)
• Inventors: Forke, Ulrich
• Primary Examiner(s): ALLEN, STEPHONE B
• Application Number:
  US09/871,312
• Publication Number:
  US 20020179815A1
• Time in Patent Office: 832 Days
• Field of Search: 250/205, 250/206, 250/214.R, 250/214.1, 250/214.AL, 250/214.B, 315/150, 315/156, 315/158, 327/514
• US Class Current: 250/205
• CPC Class Codes: H05B 39/042 by measuring the incident light
• CPC Class Codes: H05B 41/3922 and measurement of the incident light

Abstract

The present invention provides a lighting control circuit having an LED that outputs a first signal in response to being exposed to radiation, a detection circuit coupled to the LED. The detection circuit is configured to generate a second signal from the first signal. A driver circuit is coupled to the detection circuit, and the driver circuit is configured to generate a third signal to control an illumination level of one or more lights. The third signal is varied in response to the second signal.

Claims

1. A lighting control circuit comprising:

an LED that outputs a first signal in response to being exposed to radiation;

a detection circuit coupled to the LED, the detection circuit configured to generate a second signal from the first signal; and

a driver circuit coupled to the detection circuit, the driver circuit configured to generate a third signal to control an illumination level of one or more lights, wherein the third signal is varied in response to the second signal.

2. The circuit of claim 1 wherein the driver circuit receives the second signal and compares it to a fourth signal, and wherein the driver circuit is configured to match the second signal with the fourth signal via a loop, thereby either raising or lowering the illumination level of one or more lights until the second signal and the fourth signal match.

3. The circuit of claim 1 wherein the first signal is amplified.

4. The circuit of claim 1 wherein a light spectrum detected by the LED substantially mimics the photopic curve.

5. The circuit of claim 1 wherein the fourth signal is adjustable and represents a set illumination level.

6. The circuit of claim 1 wherein the lighting control circuit adjusts the ambient light in response to changes in the ambient light.

7. A lighting control circuit comprising:

an LED that outputs a first signal in response to being exposed to radiation;

a detection circuit coupled to the LED, the detection circuit configured to generate a second signal from the first signal;

a driver circuit coupled to the detection circuit, the driver circuit configured to generate a third signal to control an illumination level of one or more lights, wherein the third signal is varied in response to the second signal, and wherein the driver circuit receives the second signal and compares it to a fourth signal;

a loop comprising an opto-electric path and an electronic path, the opto-electric path traveling from a light source controlled by the lighting control circuit to the LED via the radiation from the light, the electronic path traveling from the LED to the light source via the lighting control circuit, wherein the driver circuit is configured to match the second signal to the fourth signal via the loop, thereby either raising or lowering the illumination level of one or more lights until the second signal and the fourth signal match.

8. A method for controlling the brightness level of a light, the method comprising:

exposing an LED to radiation;

outputting from the LED a first signal in response to the radiation exposure;

generating a second signal in response to detection of the first signal; and

generating a third signal to control an illumination level of one or more lights, wherein the third signal is varied in response to the second signal.

9. The method of claim 8 wherein generating the second signal comprises amplifying the first signal.

10. The method of claim 8 wherein generating the third signal comprises comparing the second signal to a fourth signal and matching the second and fourth signals.

11. The method of claim 10 wherein the step of matching further comprises adjusting an ambient light level until the second signal matches the fourth signal.

12. The circuit of claim 8 wherein a light spectrum detected by the LED substantially mimics the photopic curve.

13. A lighting control circuit comprising:

an LED that emits light when driven by a current and detects light when the current is turned off, the LED outputting a first signal in response to a detected light;

a driver circuit coupled to the LED, the first driver circuit being configured to provide a current-to-voltage transfer ratio to operate with the LED; and

a processor circuit coupled to the driver circuit, the processor circuit being configured to process the first signal and to generate a second signal, the second signal controlling an illumination level of one or more lights, the second signal being varied in response to the first signal.

14. The circuit of claim 13 wherein the LED detects a spectrum that approximates a photopic luminosity curve.

15. The circuit of claim 14 wherein the photopic luminosity curve approximates a C.I.E. relative photopic luminosity curve.

16. A lighting control circuit comprising:

an LED that emits light when driven by a current and detects light when the current is turned off, the LED outputting a first signal in response to a detected light;

a driver circuit coupled to the LED, the first driver circuit being configured to provide a current-to-voltage transfer ratio to operate with the LED; and

a multiplexer coupled to the driver circuit, the multiplexer being configured to select a first mode and a second mode, the LED having a first polarity during the first mode, the LED having a second polarity during the second mode,

wherein during the first mode the LED emits light when driven by a current, and wherein during the second mode the LED detects light and generates the first signal when the current is turned off,

wherein the lighting control circuit controls an illumination level of one or more lights in response to the first signal.

17. The circuit of claim 16 wherein the LED detects a spectrum that approximates a photopic luminosity curve.

18. The circuit of claim 16 wherein the LED alternates between the first and second modes.

19. The circuit of claim 16 wherein the multiplexer alternates between the first and second modes at a frequency greater than 50 Hz.

20. The circuit of claim 16 wherein the photopic luminosity curve approximates a C.I.E. relative photopic luminosity curve.

21. A lighting control circuit comprising an LED that outputs a first signal in response to being exposed to radiation, the lighting control circuit being configured to generate a second signal derived from the first signal, wherein the second signal controls an illumination level of one or more lights.

22. The circuit of claim 21 wherein the LED detects a spectrum that approximates a photopic luminosity curve.

23. A lighting control circuit comprising:

an LED that emits light when driven by a current and detects light when the current is turned off, the LED outputting a first signal in response to a detected light,

wherein the light control circuit is configured to supply current to the LED during a first mode and process the first signal during a second mode,

wherein during the second mode, the lighting control circuit generates a second signal derived from the first signal,

wherein the second signal controls an illumination level of one or more lights.

24. The circuit of claim 23 wherein the LED detects a spectrum that approximates a photopic luminosity curve.

25. A method for controlling the brightness level of a light, the method comprising:

exposing an LED to radiation;

outputting from the LED a first signal in response to the radiation exposure; and

generating a second signal derived from detection of the first signal, wherein the second signal controls an illumination level of one or more lights.

26. The circuit of claim 25 wherein the LED detects a spectrum that approximates a photopic luminosity curve.