INDUCTIVELY POWERED GAS DISCHARGE LAMP

• US 20070029936A1
• Filed: 08/01/2006
• Published: 02/08/2007
• Est. Priority Date: 08/03/2005
• Status: Active Grant

• Current Assignee: Access Business Group International LLC (Alticor Incorporated)
• Original Assignee: Access Business Group International LLC (Alticor Incorporated)
• Inventors: Baarman, David, Lord, John, Bachman, Wesley, Stien, Nathan
• Granted Patent: US 7,622,868 B2
• Time in Patent Office: Days
• US Class Current: 315/46
• CPC Class Codes: H01J 5/50 Means forming part of the tube or lamps for the purpose of providing electrical connection to it
• CPC Class Codes: H01J 61/54 Igniting arrangements, e.g. promoting ionisation for starting
• CPC Class Codes: H01J 61/56 One or more circuit elements structurally associated with the lamp
• CPC Class Codes: H01J 61/72 having a main light-emitting filling of easily vaporisable metal vapour, e.g. mercury
• CPC Class Codes: H05B 41/24 in which the lamp is fed by high frequency ac, or with separate oscillator frequencyH05B41/26 takes precedence
• CPC Class Codes: H05B 41/295 with semiconductor devices and specially adapted for lamps with preheating electrodes, e.g. for fluorescent lamps

Abstract

An inductively powered gas discharge lamp including both a power coil and a heating coils associated with each filament. The heating coils enable the filaments to be preheated before the starting voltage is applied through the power coils. The inductive power coils and the inductive heater coils are contained within the lamp envelope, allowing the lamp to be entirely sealed. A method of dimming the lamp also is disclosed. The lamp is dimmed by both decreasing the power applied to the power coils and increasing the power applied to the heating coils so as to prevent the arc from extinguishing under lower voltage conditions.

Claims

1. A gas discharge lamp comprising:

an envelope containing a discharge gas;

a first electrode within the envelope;

a second electrode within the envelope;

a first inductive power coil coupled with the first electrode capable of receiving power from an inductive power supply for supplying power to the first electrode; and

a first inductive heater coil connected to the first electrode capable of applying a heating current to the first electrode, the first inductive heater coil capable of receiving power from the inductive power supply.

2. The gas discharge lamp of claim 1 further comprising:

a capacitor in series with the first inductive power coil.

3. The gas discharge lamp of claim 2 further comprising:

a second inductive power coil connected to the second electrode and capable of receiving power from the inductive power supply.

4. The gas discharge lamp of claim 3 further comprising:

a second inductive heater coil connected to a second electrode and capable of receiving power from the inductive power supply.

5. The gas discharge lamp of claim 1 further comprising a capacitor coupled to the first inductive power coil, the first inductive power coil and the capacitor forming a resonant circuit.

6. The gas discharge lamp of claim 5 where the resonant circuit is one of a series resonant circuit and a parallel resonant circuit.

7. The gas discharge lamp of claim 4 where the first inductive power coil, the second power inductive coil, the first inductive heater coil, the second inductive heater coil, and the capacitor are contained within the envelope such that the envelope is unpenetrated.

8. The gas discharge lamp of claim 1 where the first inductive heater coil is contained within the perimeter of the first inductive power coil.

9. The gas discharge lamp of claim 3 where the first inductive heater coil is contained within the perimeter of the first inductive power coil and the second inductive heater coil is contained within the perimeter of the second inductive power coil.

10. The gas discharge lamp of claim 3 further comprising a conductor connecting the first inductive power coil to the second inductive power coil.

11. The gas discharge lamp of claim 10 where the conductor is within the envelope.

12. The gas discharge lamp of claim 11 where the conductor is a film of conductive material attached to the envelope.

13. The gas discharge lamp of claim 1 where the first inductive heater coil and the first inductive power coil are coplanar.

14. A gas discharge lamp comprising:

a sealed envelope containing a discharge gas;

a first electrode and a second electrode within the envelope;

a first power coil and a second power coil coupled with the first electrode and the second electrode respectively, the first power coil and the second power coil adapted to supply power to the first electrode and the second electrode respectively; and

a first heating coil and a second heating coil coupled with the first electrode and the second electrode respectively, the first heating coil and the second heating coil adapted to supplying heating currents to the first electrode and the second electrode respectively.

15. The gas discharge lamp of claim 14 further comprising a first magnetic material proximal to the first electrode and a second magnetic material proximal to the second electrode.

16. The gas discharge lamp of claim 15 further comprising a conductive material connecting the first power coil to the second power coil.

17. The gas discharge lamp of claim 16 where the conductive material is affixed to the envelope.

18. The gas discharge lamp of claim 14 where the first power coil is on an outer wall of the envelope.

19. The gas discharge lamp of claim 18 where the gas discharge lamp has a plateau, the plateau generally coaxial with the outer wall of the envelope, and the first heater coil for heating the first electrode is positioned within the plateau.

20. A method of operating a dimmable inductively powered gas discharge lamp comprising:

providing a gas discharge lamp having an envelope containing a discharge gas, the lamp further having a first electrode and a second electrode, a first power coil coupled with the first electrode, a second power coil coupled with the second electrode, a first heater coil coupled with the first electrode, and a second heater coil coupled with the second electrode;

providing power to the first and second power coils sufficient to strike an arc between the first and second electrodes;

reducing the power to the first and second power coils to dim the lamp; and

increasing the power to the first and second heater coils to increase the current through and therefore the temperature of the first and second electrodes.

21. The method of claim 20 where the power is switched between powering the lamp and heating the first electrode and the second electrode.

22. A method of operating a gas discharge lamp comprising:

providing a gas discharge lamp having an envelope containing a discharge gas, the gas discharge lamp further having a first electrode and a second electrode, a first power coil connected to the first electrode, a second power coil connected to the second electrode, a first heater coil for heating the first electrode, and a second heater coil for heating the second electrode;

applying power to the first and second heater coils to provide a heating profile to the first and second electrodes;

applying power to the first and second power coils to provide a voltage sufficient to strike the lamp;

measuring the strike voltage at which an arc initiated between the first and second electrodes; and

selectively changing the heating profile as a function of the strike voltage for use in subsequent starting of the lamp.

23. The method of claim 22 further comprising:

storing the strike voltage.

24. The method of claim 23 further comprising:

comparing a previous strike voltage with a current strike voltage.

25. A fixture for an inductively powered gas discharge lamp, the gas discharge lamp having first and second electrodes, the fixture comprising:

a first fixture portion adapted to receive a first potion of the lamp, said first fixture portion having a first power primary coil adapted to supply power to the first electrode in order operate the gas discharge lamp and a first heating primary coil adapted to supply power to the first electrode in order to heat the first electrode; and

a second fixture portion adapted to receive a second potion of the lamp, said second fixture portion having a second power primary coil adapted to supply power to the second electrode in order operate the gas discharge lamp and a second heating primary coil adapted to supply power to the second electrode in order to heat the second electrode.

26. The fixture of claim 25 where the first power primary coil is circumferentially disposed about the perimeter of the first portion.

27. The fixture of claim 26 where second portion has a top, and the first heating primary coil is located on the top.

28. The fixture of claim 26 where the first heating primary coil is disposed about the perimeter of the second portion.

29. A gas discharge lamp comprising:

an envelope;

a first electrode within the envelope;

a power coil for inductively receiving power from a first primary, the power coil connected to the first electrode; and

a heater coil for inductively receiving power from a second primary, the heater coil connected to the first electrode.

30. The gas discharge lamp of claim 29 where the envelope has a top, and the power coil is located within the top.

31. The gas discharge lamp of claim 30 where the heater coil s is located within the top.

32. The gas discharge lamp of claim 31 where the power coil is coaxial with the heater coil.

33. The gas discharge lamp of claim 32 where the power coil and the heater coil are substantially coplanar.

34. The gas discharge lamp of claim 33 where the envelope has a curved wall, and the power coil is circumferentially disposed about the curved wall.

35. The gas discharge lamp of claim 29 where the gas discharge lamp has a first cylindrical portion and a second cylindrical portion, the first cylindrical portion being coaxial with the second cylindrical portion and spaced from the second cylindrical portion.

36. The gas discharge lamp of claim 35 where the power coil is circumferentially disposed about the first cylindrical portion.

37. The gas discharge lamp of claim 36 where the heater coil is disposed about the second cylindrical portion.

38. The gas discharge lamp of claim 37 where the first cylindrical portion is longer than the second cylindrical portion.