Apparatus, method and system for providing AC line power to lighting devices
View Patent ↗An apparatus, method and system are disclosed for providing AC line power to lighting devices such as light emitting diodes (“LEDs”). A representative apparatus comprises: a plurality of LEDs coupled in series to form a plurality of segments of LEDs; first and second current regulators; a current sensor; and a controller to monitor a current level through a series LED current path, and to provide for first or second segments of LEDs to be in or out of the series LED current path at different current levels. A voltage regulator is also utilized to provide a voltage during a zero-crossing interval of the AC voltage. In a representative embodiment, first and second segments of LEDs are both in the series LED current path regulated at a lower current level compared to when only the first segment of LEDs is in the series LED current path.
1. An apparatus comprising:
a plurality of light emitting diodes couplable to receive an AC voltage, wherein the plurality of light emitting diodes is further couplable to form a plurality of segments, each segment including a light emitting diode;
a sensor configured to sense a first parameter; and
a control circuit coupled to the sensor, wherein the control circuit is configured to:
during a first part of an AC voltage interval, in response to an indication that the first parameter reached a first level, selectively include a segment in a series light emitting diode current path; and
during a second part of the AC voltage interval, in response to an indication that the first parameter reached a second level, selectively exclude the segment out of the series light emitting diode current path.
2. The apparatus of claim 1 , wherein the sensor is a current sensor, wherein the first parameter is a current level of the series light emitting diode current path, and wherein the first level is a first current level.
3. The apparatus of claim 2 , wherein the control circuit is further configured to:
maintain a current level of the series light emitting diode current path substantially constant at the first current level.
4. The apparatus of claim 1 , wherein the control circuit is further configured to:
during the first part of the AC voltage interval and in response to an indication from the sensor that the first parameter reached a third level, selectively include a next corresponding segment into the series light emitting diode current path.
5. The apparatus of claim 1 , wherein the control circuit is further configured to:
during the second part of the AC voltage interval and in response to an indication that the first parameter reached a fourth level, selectively exclude a next corresponding segment out of the series light emitting diode current path.
6. The apparatus of claim 1 , wherein the control circuit is further configured to:
determine a first plurality of time intervals corresponding to a number of segments for the first part of the AC voltage interval.
7. The apparatus of claim 6 , wherein the control circuit is further configured to:
during the first part of the AC voltage interval, at the expiration of each time interval of the first plurality of time intervals, selectively include a next segment into the series light emitting diode current path.
8. The apparatus of claim 1 , wherein the control circuit is further configured to:
determine a second plurality of time intervals corresponding to a number of segments for the second part of the AC voltage interval.
9. The apparatus of claim 8 , wherein the control circuit is further configured to:
during the second part of the AC voltage interval, at the expiration of each time interval of the second plurality of time intervals, selectively exclude a next segment out of the series light emitting diode current path.
10. The apparatus of claim 1 , wherein the control circuit is further configured to:
determine a first plurality of time intervals corresponding to a number of segments for the first part of the AC voltage interval;
determine a second plurality of time intervals corresponding to the number of segments for the second part of the AC voltage interval;
during the first part of the AC voltage interval, at the expiration of each time interval of the first plurality of time intervals, selectively include a next segment into the series light emitting diode current path; and
during the second part of the AC voltage interval, at the expiration of each time interval of the second plurality of time intervals, in a reverse order, selectively exclude the next segment out of the series light emitting diode current path.
11. A method of providing power to a plurality of light emitting diodes couplable to receive an AC voltage, the plurality of light emitting diodes couplable to form a plurality of segments each including a light emitting diode, the method comprising:
by a sensor, monitoring a first parameter;
by a control circuit, during a first part of an AC voltage interval, in response to the first parameter reaching a first level, selectively including a segment in a series light emitting diode current path; and
by the control circuit, during a second part of the AC voltage interval, in response to the first parameter reaching a second level, selectively excluding the segment from the series light emitting diode current path.
12. The method of claim 11 , wherein the sensor is a current sensor, wherein the first parameter is a current level of the series light emitting diode current path, and wherein the first level is a first current level.
13. The method of claim 12 , further comprising:
by the control circuit, maintaining a current level of the series light emitting diode current path substantially constant at the first current level.
14. The method of claim 11 , further comprising:
by the control circuit, during the first part of the AC voltage interval, in response to the first parameter reaching a third level, selectively including a next corresponding segment into the series light emitting diode current path.
15. The method of claim 11 , further comprising:
by the control circuit, during the second part of the AC voltage interval, in response to the first parameter reaching a fourth level, selectively excluding a next corresponding segment out of the series light emitting diode current path.
16. The method of claim 11 , further comprising:
by the control circuit, determining a first plurality of time intervals corresponding to a number of segments for the first part of the AC voltage interval.
17. The method of claim 16 , further comprising:
by the control circuit, during the first part of the AC voltage interval, at the expiration of each time interval of the first plurality of time intervals, selectively including a next segment into the series light emitting diode current path.
18. The method of claim 11 , further comprising:
by the control circuit, determining a second plurality of time intervals corresponding to a number of segments for the second part of the AC voltage interval.
19. The method of claim 18 , further comprising:
by the control circuit, during the second part of the AC voltage interval, at the expiration of each time interval of the second plurality of time intervals, selectively excluding a next segment out of the series light emitting diode current path.
20. The method of claim 11 , further comprising:
by the control circuit, determining a first plurality of time intervals corresponding to a number of segments for the first part of the AC voltage interval;
by the control circuit, determining a second plurality of time intervals corresponding to the number of segments for the second part of the AC voltage interval;
by the control circuit, during the first part of the AC voltage interval, at the expiration of each time interval of the first plurality of time intervals, selectively including a next segment into the series light emitting diode current path; and
by the control circuit, during the second part of the AC voltage interval, at the expiration of each time interval of the second plurality of time intervals, in a reverse order, selectively excluding the next segment out of the series light emitting diode current path.