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