POWER SAVING ARRANGEMENT FOR USE WITH A USER IMPLEMENTABLE PHASE CUT DIMMER

• US 20120086361A1
• Filed: 10/03/2011
• Published: 04/12/2012
• Est. Priority Date: 10/12/2010
• Status: Active Grant

• Current Assignee: Polaris PowerLED Technologies, LLC (Microchip Technology Incorporated)
• Original Assignee: Microsemi Corp. - Analog Mixed Signal Group, Ltd. (Microchip Technology Incorporated)
• Inventors: DARSHAN, Yair
• Granted Patent: US 9,089,019 B2
• Time in Patent Office: Days
• US Class Current: 315/307
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/12 using optical feedback
• CPC Class Codes: H05B 45/18 using temperature feedback
• CPC Class Codes: H05B 45/385 using flyback topology

Abstract

A power saving arrangement for use with a phase cut dimmer, the power saving arrangement constituted of: a power converter arranged to convert a received alternating current power signal to a direct current signal; a detector arranged to detect the presence, or absence, of the phase cut dimmer blocking a portion of an alternating current mains power sine wave from reaching the power converter; and a controllable minimum holding current circuit in communication with the received alternating current power signal, the controllable minimum holding current circuit responsive to an output of the detector, wherein in the event that the detector detects the absence of the phase cut dimmer, the controllable minimum holding current circuit is disabled such that a minimum holding current is not provided.

Claims

1. A power saving arrangement for use with a phase cut dimmer, the power saving arrangement comprising:

a power converter arranged to convert a received alternating current power signal to a direct current signal;

a detector arranged to detect the presence, or absence, of the phase cut dimmer blocking a portion of an alternating current mains power sine wave from reaching the power converter; and

a controllable minimum holding current circuit in communication with the received alternating current power signal, said controllable minimum holding current circuit responsive to an output of said detector,

wherein in the event that said detector detects the absence of the phase cut dimmer, the controllable minimum holding current circuit is disabled such that a minimum holding current is not provided.

2. The power saving arrangement according to claim 1, wherein in the event that said detector detects the presence of the phase cut dimmer, the controllable minimum holding current circuit is enabled such that the minimum holding current is provided.

3. The power saving arrangement according to claim 1, wherein said power converter comprises a primary side and a secondary side isolated from the primary side, and wherein said detector is connected to the secondary side.

4. The power saving arrangement according to claim 3, wherein said power converter comprises an auxiliary power winding isolated from the primary side, and wherein said detector is arranged to:

receive a signal comprising a reflection of the received alternating current power signal superimposed onto a direct current signal; and

subtract the direct current signal.

5. The power saving arrangement according to claim 4, wherein said power converter is a flyback converter.

6. The power saving arrangement according to claim 1, wherein said power converter comprises a flyback converter having a primary side switch connected in series with a primary side winding, said flyback converter further comprising a secondary side winding magnetically coupled with the primary side winding, and wherein said detector comprises:

a unidirectional electronic valve connected to the secondary side winding of the flyback converter, said unidirectional electronic valve arranged to output a reflection of the received alternating current signal superimposed on a direct current signal when said primary side switch is closed.

7. The power saving arrangement according to claim 6, wherein said detector further comprises:

a subtraction circuit arranged to subtract the direct current signal from the received reflection of the alternating current signal superimposed on the direct current signal and output a phase cut signal exhibiting a duty cycle, wherein the duty cycle is a function of the alternating current signal, and wherein the direct current signal is output by the secondary side winding.

8. The power saving arrangement according to claim 7, further comprising a low pass filter connected between said unidirectional electronic valve and said subtraction circuit.

9. The power saving arrangement according to claim 7, further comprising a conversion circuit arranged to convert the output phase cut signal to a phase cut level signal.

10. The power saving arrangement according to claim 9, further comprising a comparing circuit arranged to compare the phase cut level signal to a reference, wherein in the event that said phase cut level does not exceed the reference the presence of the phase cut dimmer is detected, and in the event that the phase cut level signal exceeds the reference the absence of the phase cut dimmer is detected.

11. A power saving arrangement comprising:

a detector arranged to detect the presence, or absence, of a phase cut dimmer blocking a portion of an alternating current mains power sine wave from reaching a power converter; and

a controllable minimum holding current circuit in communication with the power converter, said controllable minimum holding current circuit responsive to an output of said detector,

wherein in the event that said detector detects the absence of the phase cut dimmer, the controllable minimum holding current circuit is disabled such that a minimum holding current is not provided.

12. The power saving arrangement according to claim 11, wherein in the event that said detector detects the presence of the phase cut dimmer, the controllable minimum holding current circuit is enabled such that the minimum holding current is provided.

13. The power saving arrangement according to claim 11, further comprising a power converter, said power converter comprising a flyback converter having a primary side switch connected in series with a primary side winding, said flyback converter further comprising a secondary side winding magnetically coupled with the primary winding, and wherein said detector comprises:

a unidirectional electronic valve connected to the secondary winding of said flyback converter, said unidirectional electronic valve arranged to output a reflection of a received alternating current signal superimposed on a direct current signal when said primary side switch is closed.

14. The power saving arrangement according to claim 13, wherein said detector further comprises:

a subtraction circuit arranged to subtract the direct current signal from the received reflection of the alternating current signal superimposed on the direct current signal and output a phase cut signal exhibiting a duty cycle, wherein the duty cycle is a function of the alternating current signal, and wherein the direct current signal is output by the secondary side winding.

15. The power saving arrangement according to claim 14, further comprising a low pass filter connected between said unidirectional electronic valve and said subtraction circuit.

16. The power saving arrangement according to claim 14, further comprising a conversion circuit arranged to convert the output phase cut signal to a phase cut level signal.

17. The power saving arrangement according to claim 16, further comprising a comparing circuit arranged to compare the phase cut level signal to a reference, wherein in the event that said phase cut level does not exceed the reference the presence of the phase cut dimmer is detected, and in the event that the phase cut level signal exceeds the reference the absence of the phase cut dimmer is detected.

18. A method of providing a selectable minimum holding current, the method comprising:

receiving an alternating current power signal;

detecting the presence, or absence, of a phase cut dimmer blocking a portion of a mains power sine wave from the received alternating current power signal; and

disabling, in the event that said detecting detects the absence of the phase cut dimmer, a minimum holding current circuit such that a minimum holding current is not provided.

19. The method according to claim 18, further comprising:

enabling, in the event that said detecting detects the presence of the phase cut dimmer, the controllable minimum holding current circuit such that the minimum holding current is provided.

20. The method according to claim 18, wherein said detecting comprises:

receiving a signal comprising a reflection of the received alternating current power signal superimposed onto a direct current signal; and

subtracting the direct current signal to produce a phase cut signal which exhibits a duty cycle reflective of the unblocked portion of the alternating current power sine wave.