Title:
APPARATUS AND METHOD FOR DIMMING A GAS DISCHARGE LAMP
Document Type and Number:
WIPO Patent Application WO1999001013
Kind Code:
A3
Abstract:
A power supply for a gas discharge lamp includes a converter, a microprocessor switch control circuit, a driver, a switching network having two MOSFET switches, and an output transformer. A cross conduct inhibit circuit is connected in series between the driver and the switching network to prevent simultaneous operation of the switches. The power supply may further include a ground fault interrupt circuit and a ground continuity detector. A dimming module contains a potentiometer input device to vary the brightness of the lamp. The power supply operates at a preset level until the dimming module is connected. The dimming module cannot be removed without shutting off the power supply. The first and second MOSFETs switch first and second voltages across the transformer, thereby causing first and second drive pulses in the periodic output signal. Between the first and second and the second and first drive pulses are first and second dead times. The power supply sets the brightness level of the lamp by varying at least one of the dead time periods.
Inventors:
KASTNER MARK
Application Number:
PCT/US1998/013552
Publication Date:
March 18, 1999
Filing Date:
June 29, 1998
Export Citation:
Assignee:
EVERBRITE INC (US)
International Classes:
H05B41/285; H05B41/392; (IPC1-7): H05B41/00
Domestic Patent References:
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