THREE-WAY SOLID-STATE LIGHT BULB

• US 20150271888A1
• Filed: 03/24/2014
• Published: 09/24/2015
• Est. Priority Date: 03/24/2014
• Status: Active Grant

• Current Assignee: IDEAL Industries Lighting, LLC (Ideal Industries Incorporated)
• Original Assignee: CREE Incorporated (Wolfspeed, Inc.)
• Inventors: Reynolds, Matthew C., McIntyre, Michael
• Granted Patent: US 9,462,651 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F21K 9/232 specially adapted for generating an essentially omnidirectional light distribution, e.g. with a glass bulb
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light
• CPC Class Codes: H05B 45/40 Details of LED load circuits

Abstract

A three-way solid-state light bulb is disclosed. Embodiments of the present invention provide power supply circuitry that allows a solid-state lamp or light bulb to work in a manner similar to that of a common three-way incandescent light bulb. The power supply can selectively receive the input voltage, usually AC line voltage, on first and second input terminals. In some embodiments, a control circuit is operable to influence a feedback loop by diverting current and/or in some cases alter a current sense resistance in accordance with the selective presence of the voltage at the first and second inputs. The light output of the solid-state emitter or solid-state emitters in the bulb is set in accordance with a selective presence of the input voltage.

Claims

1. A power supply for a solid-state light bulb, the power supply comprising:

first and second inputs for receiving a voltage;

an output for connection to a solid-state light emitter; and

a control circuit connected to the first and second inputs and to a feedback input for a driver, to selectively set a light output for the solid-state light emitter by influencing a feedback loop for the driver in accordance with a selective presence of the voltage at the first and second inputs.

2. The power supply of claim 1 wherein the control circuit selectively sets the light output by using the feedback input to set a regulation point for the driver.

3. The power supply of claim 2 wherein the control circuit is operable to divert current from the feedback loop in accordance with the selective presence of the voltage at the first and second inputs.

4. The power supply of claim 3 wherein the control circuit further comprises two transistors to divert the current in accordance with a sense voltage across a resistor.

5. The power supply of claim 4 wherein the two transistors are connected in parallel.

6. The power supply of claim 4 wherein the two transistors are connected in a cascode configuration.

7. The power supply of claim 2 wherein the control circuit is operable to alter a current sense resistance for the solid-state emitter in accordance with the selective presence of the voltage at the first and second inputs.

8. The power supply of claim 7 wherein the control circuit further comprises two transistors to alter the current sense resistance in accordance with a sense voltage across a resistor.

9. The power supply of claim 8 wherein the two transistors are connected in parallel.

10. The power supply of claim 8 wherein the two transistors are connected in a cascode configuration.

11. A light emitting diode (LED) light bulb comprising:

first and second input terminals for receiving a voltage relative to a neutral terminal;

at least one LED; and

a control circuit connected to the first and second input terminals, a feedback input for a driver, and the at least one LED to selectively set a light output of the at least one LED in accordance with a selective presence of the voltage at the first and second input terminals.

12. The LED light bulb of claim 11 wherein the control circuit selectively sets the light output by using the feedback input to set a regulation point for the driver.

13. The LED light bulb of claim 12 wherein the control circuit is operable to divert current from a feedback loop in accordance with the selective presence of the voltage at the first and second input terminals.

14. The LED light bulb of claim 13 wherein the control circuit further comprises two transistors to divert the current in accordance with a sense voltage across a resistor.

15. The LED light bulb of claim 14 wherein the two transistors are connected in parallel.

16. The LED light bulb of claim 14 wherein the two transistors are connected in a cascode configuration.

17. The LED light bulb of claim 12 wherein the control circuit is operable to alter a current sense resistance for the at least one LED in accordance with the selective presence of the voltage at the first and second input terminals.

18. The LED light bulb of claim 17 wherein the control circuit further comprises two transistors to alter the current sense resistance in accordance with a sense voltage across a resistor.

19. The LED light bulb of claim 18 wherein the two transistors are connected in parallel.

20. The LED light bulb of claim 18 wherein the two transistors are connected in a cascode configuration.

21. A method of operating an light emitting diode (LED) light bulb, the method comprising:

selectively receiving an input voltage on first and second input terminals relative to a neutral terminal;

setting a light output of at least one LED in accordance with a selective presence of the input voltage on the first and second input terminals; and

causing a driver to supply power to the at least one LED to enable the at least one LED to provide the light output in accordance with the selective presence of the input voltage.

22. The method of claim 21 wherein the setting of the light output further comprises using a feedback input of a driver to set a regulation point in accordance with a sense voltage across a resistor.

23. The method of claim 22 wherein the setting of the light output further comprises diverting current from a feedback loop.

24. The method of claim 22 wherein the setting of the light output further comprises altering a current sense resistance for the at least one LED.

25. A circuit for setting light output in accordance with a selective presence of a voltage at a plurality of line inputs, the circuit comprising:

a feedback path for connection between a light emitter and a feedback input of a driver;

a sensing circuit block connected to each of the plurality of line inputs to sense the voltage at the line input; and

a control circuit block for each sensing block, each control circuit block connected to the feedback path to influence a regulation point for the driver in accordance with the presence of the voltage.

26. The circuit of claim 25 further comprising a sense resistor connected to the feedback path.

27. The circuit of claim 26 wherein the plurality of line inputs further comprises at least one pair of line inputs, each line input of the pair associated with a sensing circuit block and a control circuit block.

28. The circuit of claim 27 further comprising a pair of transistors, each transistor associated with the control circuit block and sensing circuit block of a line input.

29. The circuit of claim 28 further comprising the driver.

30. The circuit of claim 29 further comprising a light emitter connected to the driver and the feedback path.

31. The circuit of claim 28 wherein the pair of transistors are connected in parallel.

32. The circuit of claim 28 wherein the pair of transistors are connected in a cascode configuration.