Systems and methods for low-power lamp compatibility with a leading-edge dimmer and a magnetic transformer

• US 9,655,202 B2
• Filed: 03/13/2013
• Issued: 05/16/2017
• Est. Priority Date: 07/03/2012
• Status: Expired due to Fees

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Philips Lighting BV (Koninklijke Philips N.V.)
• Inventors: Melanson, John L., King, Eric Jerome, Xie, Yanhui
• Primary Examiner(s): Pham, Thai
• Assistant Examiner(s): Alaeddini, Borna
• Application Number:
  US13/799,010
• Publication Number:
  US 20140009079A1
• Time in Patent Office: 1,525 Days
• Field of Search: 315219
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/315 Reverse phase-control circuits
• CPC Class Codes: H05B 45/37 Converter circuits
• CPC Class Codes: H05B 47/17 Operational modes, e.g. switching from manual to automatic mode or prohibiting specific operations
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

A system and method for providing compatibility between a load and a secondary winding of a magnetic transformer driven at its primary winding by a trailing-edge dimmer may include determining from a magnetic transformer secondary signal a period of a half-line cycle of an output signal of the dimmer, determining from the magnetic transformer secondary signal an estimated occurrence of an end of a phase-cut angle of the dimmer, and generating a driving signal to the load based on the period and the estimated occurrence of the end of the phase-cut angle. A lamp assembly may include a lamp for generating light and a controller for controlling operation of the lamp, the controller comprising a timing control circuit for determining a period of a periodic signal received by the lamp assembly.

Claims

1. An apparatus comprising:

a controller to provide compatibility between a lamp and a secondary winding of a magnetic transformer driven at its primary winding by a leading-edge dimmer, wherein the controller is configured to;

determine from a magnetic transformer secondary signal a period of a half-line cycle of an output signal of the dimmer;

estimate from the magnetic transformer secondary signal an estimated occurrence of an end of a phase-cut angle of the dimmer; and

determine phase imbalances between phases of the magnetic transformer secondary signal based on different amplitudes between the phases,

generate a driving signal to the lamp based on the period and the estimated occurrence of the end of the phase-cut angle and the determined phase imbalances.

2. The apparatus of claim 1, wherein the controller comprises a timing control circuit to determine the period of the half-line cycle of the output signal of the dimmer.

3. The apparatus of claim 2, wherein the timing control circuit comprises a phase-locked loop.

4. The apparatus of claim 2, wherein the timing control circuit comprises a delay-locked loop.

5. The apparatus of claim 1, the controller configured to estimate the estimated occurrence of the end of the phase-cut angle based at least on a determination of an estimated time at which the magnetic transformer secondary signal exceeds a predetermined threshold magnitude.

6. The apparatus of claim 1, the controller configured to estimate the estimated occurrence of the end of the phase-cut angle based at least on a determination of an estimated time at which the magnetic transformer secondary signal falls below a predetermined threshold magnitude.

7. The apparatus of claim 1, the controller configured to estimate the estimated occurrence of the end of the phase-cut angle based on at least a determination of an estimated portion of the period in which the magnetic transformer secondary signal is greater than a predetermined threshold magnitude.

8. The apparatus of claim 1, wherein the driving signal is indicative of an intensity of light to be generated by the lamp.

9. The apparatus of claim 1, wherein the lamp comprises a light-emitting diode lamp.

10. The apparatus of claim 1, wherein the lamp comprises a lamp having a multifaceted reflector form factor.

11. A method for providing compatibility between a lamp and a secondary winding of a magnetic transformer driven at its primary winding by a leading-edge dimmer comprising:

determining from a magnetic transformer secondary signal a period of a half-line cycle of an output signal of the dimmer;

estimating from the magnetic transformer secondary signal an estimated occurrence of an end of a phase-cut angle of the dimmer;

determining phase imbalances between phases of the magnetic transformer secondary signal based on different amplitudes between the phases; and

generating a driving signal to the lamp based on the period and the estimated occurrence of the end of the phase-cut angle and the determined phase imbalances.

12. The method of claim 11, further comprising estimating the period of the half-line cycle of the output signal of the dimmer using a phase-locked loop.

13. The method of claim 11, further comprising estimating the period of the half-line cycle of the output signal of the dimmer using a delay-locked loop.

14. The method of claim 11, further comprising estimating the occurrence of the end of the phase-cut angle based at least on a determination of a time at which the magnetic transformer secondary signal exceeds a predetermined threshold magnitude.

15. The method of claim 11, further comprising estimating the occurrence of the end of the phase-cut angle based at least on a determination of a time at which the magnetic transformer secondary signal falls below a predetermined threshold magnitude.

16. The method of claim 11, further comprising estimating the occurrence of the end of the phase-cut angle based at least on a determination of a time at which the magnetic transformer secondary signal is greater than a predetermined threshold magnitude.

17. The method of claim 11, wherein the lamp comprises a light-emitting diode lamp.

18. The method of claim 11, wherein the lamp comprises a multifaceted reflector form factor.