Lighting system with lighting dimmer output mapping

• US 9,426,866 B2
• Filed: 04/01/2015
• Issued: 08/23/2016
• Est. Priority Date: 03/12/2007
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Melanson, John L., Paulos, John J.
• Primary Examiner(s): VU, JIMMY T
• Application Number:
  US14/676,449
• Publication Number:
  US 20150208484A1
• Time in Patent Office: 510 Days
• Field of Search: 315/200.R, 315/246, 315/247, 315/291, 315/307, 315/DIG.4
• US Class Current: 1/1
• CPC Class Codes: H05B 45/14 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 47/10 Controlling the light source
• CPC Class Codes: H05B 47/165 following a pre-assigned programmed sequence; Logic control [LC]

Abstract

A system and method map dimming levels of a lighting dimmer to light source control signals using a predetermined lighting output function. The dimmer generates a dimmer output signal value. At any particular period of time, the dimmer output signal value represents one of multiple dimming levels. In at least one embodiment, the lighting output function maps the dimmer output signal value to a dimming value different than the dimming level represented by the dimmer output signal value. The lighting output function converts a dimmer output signal values corresponding to measured light levels to perception based light levels. A light source driver operates a light source in accordance with the predetermined lighting output function. The system and method can include a filter to modify at least a set of the dimmer output signal values prior to mapping the dimmer output signal values to a new dimming level.

Claims

1. A method for mapping dimming output signal values of a lighting dimmer using a predetermined lighting output function and driving a light source in response to mapped digital data, the method comprising:

receiving a dimmer output signal;

detecting duty cycles of the dimmer output signal;

converting the duty cycles of the dimmer output signal into digital data representing the detected duty cycles, wherein the digital data correlates to dimming levels;

mapping the digital data to light source control signals using the predetermined lighting output function; and

generating the light source control signals to control operation of the light source.

2. The method of claim 1 further comprising:

receiving alternating current (AC) power from a voltage source on a pair of input terminals; and

receiving the dimmer output signal further comprises receiving the dimmer output signal using at least one of the input terminals.

3. The method of claim 1 wherein mapping the digital data to light source control signals using the predetermined lighting output function further comprises:

mapping the digital data to a dimming level different than the dimming level represented by the dimmer output signal value.

4. The method of claim 1 wherein:

mapping the digital data to light source control signals using the predetermined lighting output function further comprises;

mapping the digital data to a light source flickering function that causes the light source to randomly vary in intensity for a predetermined dimming range of input dimming levels.

5. The method of claim 1 wherein mapping the digital data to light source control signals using the predetermined lighting output function further comprises:

retrieving the predetermined lighting output function from a memory, wherein data in the memory associates the retrieved predetermined lighting output function with the dimming level represented by the dimmer output signal value.

6. The method of claim 1 wherein the predetermined lighting output function maps dimmer output levels to human perceived lighting output levels with an approximately linear relationship.

7. The method of claim 1 further comprising:

low pass filtering at least a set of values of the digital data representing dimming levels below a predetermined threshold level to decrease a rate of change in the perceived light of the light source indicated by the dimmer output signal duty cycles.

8. The method of claim 1 wherein the light source includes one or more lighting elements selected from the group consisting of:

one or more light emitting diodes, one or more gas discharge lamps, and one or more incandescent lamps.

9. The method of claim 1 further comprising:

receiving a clock signal having a clock signal frequency; and

wherein detecting duty cycles of the dimmer output signal further comprises detecting duty cycles of the dimmer output signal based on the clock signal frequency.

10. The method of claim 1 wherein:

values of the dimmer output signal represent duty cycles of the dimmer output signal having a range of within approximately 95% to 10% of a full duty cycle that without mapping indicate a first intensity range of light output from the light source; and

mapping the digital data to light source control signals using the predetermined lighting output function comprises mapping the digital data to light source control signals using the predetermined lighting output function to map the dimmer output signal values to the light source control signals to provide an expanded intensity range of light output from the light source to at least less than 5% of a full intensity range of light output from the light source.

11. A lighting system comprising:

a controller, the controller comprising;

a duty cycle detector to detect duty cycles of a dimmer output signal generated by a lighting dimmer;

a converter to convert the duty cycles of the dimmer output signal into digital data representing the detected duty cycles, wherein the digital data correlates to dimming levels;

circuitry to map the digital data to light source control signals using a predetermined lighting output function; and

a control signal generator to generate light source control signals to control operation of a light source.

12. The lighting system of claim 11 wherein the circuitry is configured to map the digital data to a dimming different level than the dimming level represented by the duty cycle of the dimmer output signal.

13. The lighting system of claim 11 wherein the circuitry is configured to map the digital data to the control signals using a light source flickering function that causes the light source to randomly vary in intensity for a predetermined dimming range of input dimming levels.

14. The lighting system of claim 11 wherein the circuitry to map the dimmer output signal value comprises a memory having data associating the retrieved predetermined lighting output function with the dimming level represented by the duty cycles of the dimmer output signal.

15. The lighting system of claim 11 wherein the lighting output function linearly maps duty cycles of the digital output signal to human perceived lighting output levels.

16. The lighting system of claim 11 further comprising:

a filter to filter at least a set value of the digital data prior to mapping the dimmer output signal values, wherein the filter has a transfer function to low pass filter values of the digital data representing dimming levels below a predetermined threshold level to decrease a rate of change in the perceived light of the light source indicated by the duty cycles of the dimmer output signal.

17. The lighting system of claim 11 wherein the light source includes one or more lighting elements selected from the group consisting of:

one or more light emitting diodes, one or more gas discharge lamps, and one or more incandescent lamps.

18. The lighting system of claim 11 further comprising:

the light source; and

a switching power converter, coupled to the controller and the light source, wherein the switching power converter includes a switch having a control terminal to receive the light source control signals and the switch is configured to operate the light source in accordance with the light source control signals.

19. The lighting system of claim 11:

wherein the controller is further configured to receive a clock signal having a clock signal frequency; and

the duty cycle detector is further configured to detect duty cycles of the dimmer output signal based on the clock signal frequency.

20. The lighting system of claim 11 wherein:

values of the dimmer output signal represent duty cycles of the dimmer output signal having a range of within approximately 95% to 10% of a full duty cycle that without mapping indicate a first intensity range of light output from the light source; and

circuitry to map the digital data to light source control signals using a predetermined lighting output function comprises circuitry to map the digital data to light source control signals using the predetermined lighting output function to map the dimmer output signal values to the light source control signals to provide an expanded intensity range of light output from the light source to at least less than 5% of a full intensity range of light output from the light source.