Method and apparatus for operating a light emitting diode with a dimmer

• US 20080180036A1
• Filed: 01/31/2007
• Published: 07/31/2008
• Est. Priority Date: 01/31/2007
• Status: Active Grant

• Current Assignee: Lighting Science Group Corporation (Pegasus Capital Advisors, L.P.)
• Original Assignee: Lighting Science Group Corporation (Pegasus Capital Advisors, L.P.)
• Inventors: Maxik, Fredric S., Garrity, Paul J.
• Granted Patent: US 7,633,779 B2
• Time in Patent Office: Days
• US Class Current: 315/227R
• CPC Class Codes: H05B 45/31 Phase-control circuits
• CPC Class Codes: H05B 45/3725 Switched mode power supply [SMPS]
• CPC Class Codes: Y02B 20/30 Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED]
• CPC Class Codes: Y10S 315/04 Dimming circuit for fluorescent lamps

Abstract

A circuit includes an input and an output, and an electronic light generator drive portion that is coupled to the input and drives the output. In one configuration, the circuit includes a further portion that is coupled to the input and that tunes a resonance at the input to a first frequency, the further portion having an additional portion with a resonance that is tuned to a second frequency different from the first frequency, and that effects damping of the first frequency at the input. In a different configuration, the drive portion includes an electronic switch coupled to the output of the circuit, and a further portion coupled to the input and having a phase tracking portion, the phase tracking portion tracking a phase of a signal at the input and producing a control signal that is used to control the electronic switch.

Claims

1. An apparatus comprising a circuit that includes:

an input;

an output;

an electronic light generator drive portion that is coupled to said input and that drives said output; and

a further portion that is coupled to said input and that tunes a resonance at said input to a first frequency, said further portion having an additional portion with a resonance that is tuned to a second frequency different from said first frequency, and that effects damping of said first frequency at said input.

2. An apparatus according to claim 1, wherein said second frequency is more than a decade lower than said first frequency.

3. An apparatus according to claim 2, wherein said first frequency corresponds to a resonant frequency of a triac.

4. An apparatus according to claim 2,

wherein said electronic light generator drive portion can selectively supply a high frequency signal to said output of said circuit;

and

wherein said further portion effects high frequency filtering to isolate said high frequency signal from said input of said circuit.

5. An apparatus according to claim 1, including:

a light bulb housing having a transparent portion and an electrical connector portion; and

an electronic light generator disposed within said housing, said circuit being disposed within said housing with said input thereof coupled to said connector portion and said output thereof coupled to said electronic light generator, light from said electronic light generator passing through said transparent portion of said housing.

6. An apparatus according to claim 5,

wherein said electrical connector portion is an Edison base;

and

wherein said circuit is disposed substantially within said Edison base.

7. An apparatus according to claim 1,

wherein said input includes first and second terminals;

wherein said further portion includes a diode bridge having two input terminals and two output terminals;

wherein said additional portion includes first and second inductors each having a first end coupled to a respective one of said first and second terminals and having a second end coupled to a respective one of said input terminals of said diode bridge; and

wherein said additional portion includes a capacitor having first and second ends that are each coupled to a respective one of said output terminals of said diode bridge, and a resistor having first and second ends that are each coupled to a respective one of said output terminals of said diode bridge.

8. An apparatus according to claim 7,

wherein said electronic light generator drive portion includes an electronic switch that is coupled to said output of said circuit, and includes a control portion that has a control input and that controls said electronic switch as a function of said control input;

and

wherein said further portion includes two Zener diodes coupled in series with each other between said output terminals of said diode bridge, said control input of said control portion being coupled to a circuit node between said diodes.

9. An apparatus according to claim 8, wherein said further portion includes a resistor disposed between and coupled in series with said diodes, said circuit node being located between said resistor and one of said diodes.

10. An apparatus according to claim 7,

wherein said further portion includes a capacitor with each of its ends coupled to a respective one of said first and second terminals of said input;

wherein said further portion includes a resistor with each of its ends coupled to said second end of a respective one of said inductors; and

wherein said electronic light generator drive portion includes a further diode bridge having two input terminals that are each coupled to said second end of a respective one of said inductors.

11. An apparatus comprising a circuit that includes:

an input;

an output;

an electronic light generator drive portion that is coupled to said input and said output, said electronic light generator drive portion including an electronic switch that is coupled to said output of said circuit, and including a control portion that has a control input and that controls said electronic switch as a function of said control input; and

a further portion that is coupled to said input and that includes a phase tracking portion, said phase tracking portion tracking a phase of a signal at said input and producing a control signal that is coupled to said control input of said control portion.

12. An apparatus according to claim 11, wherein said phase tracking portion includes two Zener diodes coupled in series with each other, said control signal being obtained from a circuit node that is located between said diodes and that is coupled to said control input of said control portion.

13. An apparatus according to claim 12, wherein said phase tracking circuit includes a resistor disposed between and coupled in series with said diodes, said circuit node being located between said resistor and one of said diodes.

14. An apparatus according to claim 12, wherein said further portion tunes a resonance at said input to a first frequency, and has an additional portion with a resonance that is tuned to a second frequency different from said first frequency, and that effects damping of said first frequency at said input.

15. An apparatus according to claim 14,

wherein said input includes first and second terminals;

wherein said further portion includes a diode bridge having two input terminals and two output terminals;

wherein said additional portion includes first and second inductors each having a first end coupled to a respective one of said first and second terminals and having a second end coupled to a respective one of said input terminals of said diode bridge;

wherein said additional portion includes a capacitor having first and second ends that are each coupled to a respective one of said output terminals of said diode bridge, and a resistor having first and second ends that are each coupled to a respective one of said output terminals of said diode bridge; and

wherein said zener diodes are coupled in series between said output terminals of said diode bridge.

16. An apparatus according to claim 11 including:

a light bulb housing having a transparent portion and an electrical connector portion; and

an electronic light generator disposed within said housing, said circuit being disposed within said housing with said input thereof coupled to said connector portion and said output thereof coupled to said electronic light generator, light from said electronic light generator passing through said transparent portion of said housing.

17. A method of operating a circuit having an input and an output, comprising:

tuning a resonance at said input to a first frequency;

damping said first frequency at said input with circuitry having a resonance tuned to a second frequency different from said first frequency; and

supplying to said output an electronic light generator drive signal.

18. A method according to claim 17, including selecting said second frequency to be more than a decade lower than said first frequency.

19. A method according to claim 17, including:

carrying out said supplying in a manner that causes said drive signal to include a high frequency component; and

effecting high frequency filtering to isolate said input from said drive signal.

20. A method according to claim 17,

including tracking a phase of a signal at said input to produce a control signal;

and

wherein said supplying includes selectively supplying a high frequency signal to said output as a function of said control signal.

21. A method of operating a circuit having an input and an output, comprising:

tracking a phase of a signal at said input to produce a control signal; and

supplying to said output an electronic light generator drive signal, including selectively supplying a high frequency signal to said output as a function of said control signal.

22. A method according to claim 21, including:

tuning a resonance at said input to a first frequency; and

damping said first frequency at said input with circuitry having a resonance tuned to a second frequency different from said first frequency.

23. A method according to claim 21, including effecting high frequency filtering to isolate said input from said high frequency signal.