Time division modulation with average current regulation for independent control of arrays of light emitting diodes

• US 8,264,169 B2
• Filed: 02/02/2011
• Issued: 09/11/2012
• Est. Priority Date: 11/21/2006
• Status: Active Grant

• Current Assignee: Chemtron Research LLC (Intellectual Ventures LLC)
• Original Assignee: Point Somee LLC (Intellectual Ventures LLC)
• Inventors: Shteynberg, Anatoly, Rodriguez, Harry
• Primary Examiner(s): Vu, David Hung
• Application Number:
  US13/019,764
• Publication Number:
  US 20110187276A1
• Time in Patent Office: 587 Days
• Field of Search: 315/185.R, 315/186, 315/187, 315/193, 315/191, 315/294, 315/295, 315/307, 315/308, 315/291
• US Class Current: 315/307
• CPC Class Codes: H05B 45/22 using optical feedback
• CPC Class Codes: H05B 45/24 using electrical feedback from LEDs or from LED modules
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: H05B 45/38 using boost topology
• CPC Class Codes: H05B 45/46 having LEDs disposed in parallel lines
• CPC Class Codes: H05B 45/48 having LEDs organised in strings and incorporating parallel shunting devices
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]

Abstract

Representative method and computer-readable medium embodiments provide for sourcing current to a series of light emitting diodes in a plurality of series of light emitting diodes. A representative method comprises generating a current, sequentially and separately switching the current to each of the series of light emitting diodes in the plurality of series of light emitting diodes for a corresponding period of time, and predicting an output voltage across a selected series of light emitting diodes using a plurality of parameters stored in a memory.

Claims

1. A method of providing power to a series of light emitting diodes in a plurality of series of light emitting diodes, the method comprising:

generating a series current;

measuring the series current using a first current sensor;

using a controller, sequentially and separately switching the series current to each of the series of light emitting diodes in the plurality of series of light emitting diodes for a corresponding period of time; and

using the controller, predicting an output voltage across a selected series of light emitting diodes using a plurality of parameters stored in a memory, wherein the plurality of parameters corresponds to the plurality of series of light emitting diodes.

2. The method of claim 1, further comprising:

using the controller, switching no current to all remaining series of light emitting diodes while switching the series current to a selected series of light emitting diodes in the plurality of series of light emitting diodes.

3. The method of claim 1, further comprising:

using the controller, determining a source current as about equal to a sum of a plurality of corresponding series currents through the plurality of series of light emitting diodes.

4. The method of claim 3, further comprising:

using the controller, determining a total period for switching the series current to all of the series of light emitting diodes in the plurality of series of light emitting diodes.

5. The method of claim 4, further comprising:

using the controller, determining a corresponding time period for switching the series current to a selected corresponding series of light emitting diodes as about equal to a proportion of the total period determined as a ratio of the corresponding series current for the selected corresponding series of light emitting diodes to the source current.

6. The method of claim 1, further comprising:

storing, as a look up table in the memory, the plurality of parameters corresponding to the plurality of series of light emitting diodes.

7. The method of claim 1, further comprising:

measuring a corresponding output voltage for each series of light emitting diodes in the plurality of series of light emitting diodes.

8. The method of claim 7, further comprising:

using the controller, updating the predicted output voltage across a selected series of light emitting diodes in the plurality of series of light emitting diodes based on the corresponding measured output voltage.

9. The method of claim 1, further comprising:

using a voltage sensor, determining a corresponding output voltage for each series of light emitting diodes in the plurality of series of light emitting diodes.

10. The method of claim 1, further comprising:

using at least one second current sensor, measuring a corresponding current through each series of light emitting diodes in the plurality of series of light emitting diodes.

11. The method of claim 10, further comprising:

using the controller, determining the corresponding period of time for switching the series current to a selected series of light emitting diodes based on a comparison of the measured corresponding current to a predetermined current for the selected series of light emitting diodes.

12. The method of claim 1, further comprising:

using the controller, determining the corresponding period of time for switching the series current to a selected series of light emitting diodes based on an integer multiple of a period of switching.

13. The method of claim 1, further comprising:

using the controller, switching the series current to a selected series of light emitting diodes in the plurality of series of light emitting diodes if the series current is substantially zero.

14. The method of claim 1, further comprising:

using the controller and in response to a first input, adjusting an output brightness of the plurality of series of light emitting diodes by modifying each corresponding period of time of current switching to each of the series of light emitting diodes.

15. The method of claim 1, further comprising:

using the controller and in response to a second input, adjusting an output color of the plurality of series of light emitting diodes by modifying a corresponding period of time of current switching to at least one of the series of light emitting diodes in the plurality of series of light emitting diodes.

16. A method of providing power to an array of light emitting diodes in a plurality of arrays of light emitting diodes, the method comprising:

generating an input current;

measuring the input current using a first current sensor;

using a controller, switching the input current to each array of light emitting diodes in the plurality of arrays of light emitting diodes for a corresponding period of time;

measuring a corresponding output voltage for each array of light emitting diodes in the plurality of arrays of light emitting diodes;

using the controller, predicting an output voltage across a selected array of light emitting diodes using a plurality of parameters stored in a memory, wherein the plurality of parameters corresponds to the plurality of arrays of light emitting diodes; and

updating the predicted output voltage based on a corresponding measured output voltage.

17. The method of claim 16, further comprising:

using a second current sensor, measuring a corresponding current through an array of light emitting diodes in the plurality of arrays of light emitting diodes; and

using the controller, determining the corresponding period of time for switching the input current to a selected array of light emitting diodes based on a comparison of the measured corresponding current to a predetermined current for the selected array of light emitting diodes.

18. A method of providing power to an array of light emitting diodes in a plurality of arrays of light emitting diodes, the method comprising:

generating an input current;

measuring the input current using a first current sensor;

using a controller, switching the input current to each array of light emitting diodes in the plurality of arrays of light emitting diodes for a corresponding period of time;

using the controller, predicting an output voltage across a selected array of light emitting diodes using a plurality of parameters stored in a memory, wherein the plurality of parameters corresponds to the plurality of arrays of light emitting diodes; and

using at least one second current sensor, measuring a corresponding current through each array of light emitting diodes in the plurality of arrays of light emitting diodes.

19. The method of claim 18, further comprising:

using the controller, determining the corresponding period of time for switching the input current to a selected array of light emitting diodes based on a comparison of the measured corresponding current to a predetermined current for the selected array of light emitting diodes.

20. A computer-readable medium having instructions stored thereon that, in response to execution by a computing device, cause the computing device to:

generate a current;

measure the current using a first current sensor;

sequentially and separately switch the current to each of a series of light emitting diodes in a plurality of series of light emitting diodes for a corresponding period of time; and

predict an output voltage across a selected series of light emitting diodes using a plurality of parameters stored in a memory, wherein the plurality of parameters corresponds to the plurality of series of light emitting diodes.

21. The computer-readable medium of claim 20, further comprising instructions that, in response to execution by the computing device, cause the computing device to switch the series current to a selected series of light emitting diodes in the plurality of series of light emitting diodes while switching no current to all remaining series of light emitting diodes.

22. The computer-readable medium of claim 20, further comprising instructions that, in response to execution by the computing device, cause the computing device to determine a source current as about equal to a sum of a plurality of corresponding series currents through the plurality of series of light emitting diodes.

23. The computer-readable medium of claim 22, further comprising instructions that, in response to execution by the computing device, cause the computing device to determine a total period for switching the series current to all of the series of light emitting diodes in the plurality of series of light emitting diodes.

24. The computer-readable medium of claim 23, further comprising instructions that, in response to execution by the computing device, cause the computing device to determine a corresponding time period for switching the series current to a selected corresponding series of light emitting diodes as about equal to a proportion of the total period determined as a ratio of the corresponding series current for the selected corresponding series of light emitting diodes to the source current.

25. A computer-readable medium having instructions stored thereon that, in response to execution by a computing device, cause the computing device to:

generate an input current;

measure the input current using a first current sensor;

switch the input current to each array of light emitting diodes in a plurality of arrays of light emitting diodes for a corresponding period of time;

measure a corresponding output voltage for each array of light emitting diodes in the plurality of arrays of light emitting diodes;

predict an output voltage across a selected array of light emitting diodes using a plurality of parameters stored in a memory, wherein the plurality of parameters corresponds to the plurality of light emitting diodes; and

update the predicted output voltage based on a corresponding measured output voltage.

26. The computer-readable medium of claim 25, further comprising instructions that, in response to execution by the computing device, cause the computing device to:

use at least one second current sensor to measure a corresponding current through at least one array of light emitting diodes on the plurality of arrays of light emitting diodes; and

using the controller, determining the corresponding period of time for switching the input current to a selected array of light emitting diodes based on a comparison of the measured corresponding current to a predetermined current for the selected array of light emitting diodes.

27. A computer-readable medium having instructions stored thereon that, in response to execution by a computing device, cause the computing device to:

generate an input current;

measure the input current using a first current sensor;

switch the input current to each array of light emitting diodes in a plurality of arrays of light emitting diodes for a corresponding period of time;

predict an output voltage across a selected array of light emitting diodes using a plurality of parameters stored in a memory, wherein the plurality of parameters corresponds to the plurality of light emitting diodes; and

measure a corresponding current through each array of light emitting diodes in the plurality of arrays of light emitting diodes using at least one second current sensor.

28. The computer-readable medium of claim 27, further comprising instructions that, in response to execution by the computing device, cause the computing device to determine the corresponding period of time for switching the input current to a selected array of light emitting diodes based on a comparison of the measured corresponding current to a predetermined current for the selected array of light emitting diodes.