Systems and methods for minimizing power dissipation in a low-power lamp coupled to a trailing-edge dimmer
A controller may predict an estimated occurrence of a high-resistance state of a dimmer, wherein the high-resistance state occurs when the dimmer begins phase-cutting an alternating current voltage signal. The controller may also be configured to operate in a trailing-edge exposure mode for a period of time wherein the period of time includes a time of the estimated occurrence of the high-resistance state in order to allow the controller to detect the occurrence of the high-resistance state, wherein energy is transferred from an input to a dissipative element during the trailing-edge exposure mode. The controller may further be configured to minimize a time between a beginning of the period of time and the estimated occurrence of the high-resistance state by modifying the period of time based on an estimated charging time of a capacitor of the dimmer.
1. An apparatus comprising:
a controller to provide compatibility between a load and a trailing-edge dimmer, wherein the controller is configured to:
predict based on an input signal received at an input an estimated occurrence of a high-resistance state of a trailing-edge dimmer coupled to the load, wherein the high-resistance state occurs when the trailing-edge dimmer begins phase-cutting an alternating current voltage signal;
operate in a trailing-edge exposure mode for a period of time wherein the period of time includes a time of the estimated occurrence of the high-resistance state in order to allow the controller to detect the occurrence of the high-resistance state, wherein energy is transferred from the input to a dissipative element during the trailing-edge exposure mode; and
minimize a time between a beginning of the period of time and the estimated occurrence of the high-resistance state by:
estimating a charging time of a capacitor of the trailing-edge dimmer; and
modifying the period of time based on the charging time.
2. The apparatus of claim 1 , wherein the dissipative element comprises the load.
3. The apparatus of claim 1 , wherein the dissipative element comprises an element other than the load.
4. The apparatus of claim 1 , wherein estimating the charging time comprises at least one of:
estimating a fall time of the input signal; and
estimating a control setting of the trailing-edge dimmer based on the input signal.
5. The apparatus of claim 1 , wherein:
estimating the charging time comprises:
estimating a partial fall time of the input signal; and
estimating a control setting of the trailing-edge dimmer based on the input signal; and
modifying the period of time comprises:
estimating an actual fall time equal to the partial fall time multiplied by a multiplier which is a function of the control setting; and
setting a duration of the period of time equal to the actual fall time.
6. The apparatus of claim 1 , wherein the controller is further configured to operate such that a low input impedance is provided at the input during the trailing-edge exposure mode.
7. The apparatus of claim 1 , wherein the controller is further configured to operate in a glue mode immediately after the period of time, such that a power converter provides a low input impedance to the input during the glue mode.
8. The apparatus of claim 1 , wherein the load comprises a lamp.
9. The apparatus of claim 8 , wherein the lamp comprises a light-emitting diode lamp.
10. The apparatus of claim 8 , wherein the lamp further comprises a multifaceted reflector form factor.
11. A method for providing compatibility between a load and a trailing-edge dimmer coupled to the load comprising:
predicting based on an input signal received at an input an estimated occurrence of a high-resistance state of the trailing-edge dimmer, wherein the high-resistance state occurs when the trailing-edge dimmer begins phase-cutting an alternating current voltage signal;
operating in a trailing-edge exposure mode for a period of time wherein the period of time includes a time of the estimated occurrence of the high-resistance state in order to allow a controller to detect the occurrence of the high-resistance state, wherein energy is transferred from the input to a dissipative element during the trailing-edge exposure mode; and
minimizing a time between a beginning of the period of time and the estimated occurrence of the high-resistance state by:
estimating a charging time of a capacitor of the trailing-edge dimmer; and
modifying the period of time based on the charging time.
12. The method of claim 11 , wherein the dissipative element comprises the load.
13. The method of claim 11 , wherein the dissipative element comprises an element other than the load.
14. The method of claim 11 , wherein estimating the charging time comprises at least one of:
estimating a fall time of the input signal; and
estimating a control setting of the trailing-edge dimmer based on the input signal.
15. The method of claim 11 , wherein:
estimating the charging time comprises:
estimating a partial fall time of the input signal; and
estimating a control setting of the trailing-edge dimmer based on the input signal; and
modifying the period of time comprises:
estimating an actual fall time equal to the partial fall time multiplied by a multiplier which is a function of the control setting; and
setting a duration of the period of time equal to the actual fall time.
16. The method of claim 11 , further comprising operating such that a low input impedance is provided at the input during the trailing-edge exposure mode.
17. The method of claim 11 , further comprising operating in a glue mode immediately after the period of time, such that a low input impedance is provided at the input during the glue mode.
18. The method of claim 11 , wherein the load comprises a lamp.
19. The method of claim 18 , wherein the lamp comprises a light-emitting diode lamp.
20. The method of claim 18 , wherein the lamp further comprises a multifaceted reflector form factor.