USER CONTROL OF AN LED LUMINAIRE FOR A PHASE CUT DIMMER

• US 20120194091A1
• Filed: 01/19/2012
• Published: 08/02/2012
• Est. Priority Date: 01/31/2011
• 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 8,541,952 B2
• Time in Patent Office: Days
• US Class Current: 315/209.R
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light

Abstract

A phase cut angle converter with range detection for a phase cut dimmer constituted of: a phase cut angle detector arranged to detect the phase cut angle presented by the phase cut dimmer blocking a portion of an alternating current mains power sine wave from reaching a power converter, and output a signal whose value is responsive to the detected phase cut angle; a storage functionality constituted of a memory in communication with the phase cut angle detector, the storage functionality arranged to detect each of a minimum value and a maximum value for the detected phase cut angle of the phase cut angle detector and store the minimum value and the maximum value on the memory; and a signal adjustment functionality arranged to convert the detected phase cut angle to a dimming signal responsive to the stored minimum value and the maximum value for the detected phase cut angle.

Claims

1. A phase cut angle converter with range detection for a phase cut dimmer comprising:

a phase cut angle detector arranged to detect the phase cut angle presented by the phase cut dimmer blocking a portion of an alternating current mains power sine wave and output a phase cut level signal whose value is responsive to the detected phase cut angle;

a storage functionality comprising a memory, said storage functionality in communication with said phase cut angle detector and arranged to detect each of a minimum value and a maximum value for the phase cut level signal and store said minimum value and said maximum value on said memory; and

a signal adjustment functionality arranged to convert the phase cut level signal to a dimming signal responsive to said stored minimum value and said maximum value for the detected phase cut angle.

2. The phase cut angle converter with range detection of claim 1, wherein said storage functionality further comprises a comparing functionality arranged to:

determine if the phase cut level signal is less than the stored minimum value and update said stored minimum value with the current value of the phase cut level signal in the event that the phase cut level signal is less than the stored minimum value; and

determine if the phase cut level signal is greater than the stored maximum value and update said stored maximum value with the current value of the phase cut level signal in the event that the phase cut level signal is greater than the stored maximum value.

3. The phase cut angle converter with range detection according to claim 1, further comprising a power converter arranged to convert the received alternating current power signal to a direct current signal, wherein said power converter comprises a primary side and a secondary side isolated from the primary side, and wherein said phase cut angle detector is connected to the secondary side.

4. The phase cut angle converter with range detection according to claim 3, wherein said power converter comprises an auxiliary power winding isolated from the primary side, and wherein said phase cut angle 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 from the received signal.

5. The phase cut angle converter with range detection according to claim 4, wherein said power converter is a flyback converter.

6. The phase cut angle converter with range detection 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 phase cut angle 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 phase cut angle converter with range detection according to claim 6, wherein said detector further comprises:

a phase cut detector 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 phase cut angle converter with range detection according to claim 7, further comprising a low pass filter connected between said unidirectional electronic valve and said phase cut detector.

9. The phase cut angle converter with range detection according to claim 7, further comprising a conversion circuit arranged to convert the output of said phase cut detector to the phase cut angle signal.

10. A method of converting a phase cut angle to a dimming signal, the method comprising:

receiving an alternating current power signal;

detecting the phase cut angle presented by a phase cut dimmer blocking a portion of the received alternating current power signal;

storing each of a minimum value and a maximum value for the detected phase cut angle of said phase cut angle detector; and

converting the detected phase cut angle to a dimming signal responsive to the stored minimum value and the maximum value for the detected phase cut angle.

11. The method according to claim 10, wherein said storing each of the minimum value and the maximum value comprises:

determining if the detected phase cut angle is less than the stored minimum value and updating the stored minimum value with the detected phase cut angle in the event that the detected phase cut angle is less than the stored minimum value; and

determining if the detected phase cut angle is greater than the stored maximum value and updating the stored maximum value with the detected phase cut angle in the event that the detected phase cut angle is greater than the stored maximum value.

12. The method according to claim 10, wherein said detecting the phase cut angle 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 from the received signal to produce a phase cut signal which exhibits a duty cycle reflective of the unblocked portion of the alternating current power sine wave.

13. The method according to claim 12, wherein said detecting the phase cut angle further comprises:

prior to said subtracting, low pass filtering said received signal comprising a reflection of the received alternating current power signal superimposed onto a direct current signal.

14. The method according to claim 12, further comprising:

converting the produced phase cut signal to a phase cut level signal.