(54) POWER SUPPLY FOR GAS DISCHARGE LAMP
(75) Inventors: Mark Kastner; Harry M. Pyne, both of New Berlin, WI (US)
(73) Assignee: Everbrite, Inc., Greenfield, WI (US)
( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 0 days.
(21) Appl. No.: 09/719,322
(22) PCT Filed: Jun. 30, 1999
(86) PCT No.: PCT/US99/14860
§ 371 (c)(1),
(2), (4) Date: Feb. 5, 2001
(87) PCT Pub. No.: WO00/02423 PCT Pub. Date: Jan. 13, 2000
Related U.S. Application Data
(60) Provisional application No. 60/091,449, filed on Jul. 1, 1998.
(51) Int. C I. G05F 1 00
(52) U.S. CI 315/307; 315/219; 315/309;
(58) Field of Search 315/307, 219,
315/224, 225, 276, 279, 282, 283, 291, 302, 309, 308, 360
A power supply for a gas discharge lamp is claimed. An input circuit receives power from a power source. An output transformer having a primary winding and a secondary winding and has a lamp connected in circuit across the secondary winding. First and second power switches switch power to the primary winding. The driver drives the power switches at a drive frequency. A tuned LC resonant circuit having a resonant frequency is connected in circuit between the driver and the lamp. A controller generates control signals to the driver at a first frequency that is functionally related to the drive frequency, and regulates the lamp current by controlling the difference between the resonant frequency and the first frequency.
75 Claims, 10 Drawing Sheets