SIMO CONVERTERS THAT GENERATE A LIGHT OUTPUT

• US 20130154508A1
• Filed: 12/15/2011
• Published: 06/20/2013
• Est. Priority Date: 12/15/2011
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Gilliom, Michael
• Granted Patent: US 8,841,860 B2
• Time in Patent Office: Days
• US Class Current: 315/297
• CPC Class Codes: H02M 1/009 having two or more independently controlled outputs for DC-DC converter with intermediate AC H02M3/33561
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 3/33561 having more than one ouput with independent control
• CPC Class Codes: H05B 45/375 using buck topology
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/385 using flyback topology

Abstract

A power converter includes a single magnetic element in communication with a plurality of output channels. Each output channel includes one or more light-emitting diodes (LEDs) that may output a desired light output. Desired amounts of current may be discharged from the single magnetic element through the LEDs to generate the desired light output. The current may be drawn through the LEDs by switching “on” and “off” switches connected to the LEDs. A controller in communication with the power converter may generate switching signals to turn “on” and “off” the switches to draw the desired amounts of current. The controller may measure the current and determine whether to adjust the switching signals if the measured current draw is not the desired current draw in order to generate the desired light output from the LEDs.

Claims

1. A system comprising:

a power converter comprising;

a single magnetic element;

a plurality of output loads in communication with the single magnetic element, the plurality of output loads configured to draw current discharged from the single magnetic element,

wherein the plurality of output loads are configured to output a predetermined light output.

2. The system of claim 1, further comprising:

a controller in communication with the power converter, the controller configured to control current conduction through the power converter to generate the predetermined light output.

3. The system of claim 2, wherein the controller comprises a signal generator that is configured to output switching signals to the power converter to draw an amount of current through the plurality of output loads to output the predetermined light output.

4. The system of claim 1, wherein the controller further comprises:

an accumulator module that is configured to measure the discharged current drawn through the plurality of output loads; and

a comparator module that is configured to determine a difference in current draw between the measured current draw and the predetermined current draw,

wherein the signal generator module is configured to adjust the switching signals to compensate for the difference in current draw between the measured current draw and the predetermined current draw.

5. The system of claim 4, wherein the controller further comprises:

a compensator module that is configured to adjust one or more timing parameters in response to the determination of the difference in current draw, the one or more timing parameters being used to adjust the switching signals to compensate for the difference in current draw.

6. The system of claim 5, wherein the timing parameters comprise at least one of a charge period or one or more fixed ratios of channel conduction periods.

7. The system of claim 4, wherein the measured current draw comprises a measured current draw for each channel,

wherein the predetermined current draw comprises a predetermined current draw for each channel, and

wherein the comparator module is to determine a difference in current draw between the measured current draws and the predetermined current draws for each channel.

8. The system of claim 4, wherein the accumulator module is configured to measure the discharged current drawn through the LEDs and the comparator module is configured to determine the difference in current draw between the measured current draw and the predetermined current draw every sample period.

9. The system of claim 1, wherein the desired amount of current draw is based on at least one of a color point, a brightness, an operating temperature of the plurality of output loads, or a lifetime of the plurality of output loads.

10. The system of claim 1, wherein the plurality of output loads comprises a plurality of light emitting diodes (LEDs).

11. The system of claim 10, wherein the plurality of LEDs are configured in a red-green-blue (RGB) configuration.

12. The system of claim 10, wherein the plurality of LEDs are configured in a blue-shifted yellow (BSY) configuration.

13. The system of claim 1, wherein the single magnetic element comprises a transformer.

14. The system of claim 1, wherein the single magnetic element comprises an inductor.

15. The system of claim 1, wherein the power converter comprises one of a SIMO flyback converter, a SIMO boost converter, or a SIMO buck converter.

16. A power converter comprising:

a single magnetic element;

a plurality of output channels in communication with the single magnetic element, the plurality of output channels being configured to receive current from the single magnetic element;

wherein each output channel comprises an output load, in communication with a switch, the output loads being configured to output a light output, and

wherein at least some of the switches are configured to receive switching signals that turn “

on” and

“

off”

the switches to draw current through the output loads, the plurality of output loads being configured to output the light output when the current is drawn through the output loads.

17. The power converter of claim 16, wherein one of the switches comprises a passive switch, and the other of the switches comprise active switches that are configured to receive the switching signals.

18. The power converter of claim 16, wherein the plurality of output loads comprises light emitting diodes (LEDs).

19. A method of outputting a light output from a power converter comprising a single magnetic element in communication with a plurality of output loads, the method comprising:

storing current in the single magnetic element during a charge period of a switching cycle;

discharging the current from the single magnetic element through the output loads during a discharge period of the switching cycle, the current being discharged through the loads to output the light output.

20. The method of claim 19, further comprising:

determining, with at least one controller, a predetermined current draw through the loads to generate the desired light output.

21. The method of claim 20, wherein determining the predetermined current draw comprises determining a predetermined current draw for each of the output channels over a sample period.

22. The method of claim 19, further comprising:

generating, with at least one controller, switching signals to turn “

on” and

“

off”

switches in communication with the plurality of output loads in the output channels to draw current through the loads to output the light output.

23. The method of claim 19, further comprising:

measuring, with at least one first controller, current being drawn through the loads during a sample period; and

comparing, with at least one second controller, the measured current draw with the desired current draw to determine a difference in current draw.

24. The method of claim 23, further comprising:

adjusting, with at least one third controller, one or more characteristics of the switching signals to compensate for the difference in current draw.

25. The method of claim 24, wherein adjusting one or more characteristics of the switching signals comprises adjusting one or more duty cycles of one or more of the switching signals.

26. The method of claim 23, wherein the first controller and the second controller are the same controller.

27. The method of claim 23, wherein the first controller and the second controller are different controllers.