Title:
ELECTRONIC BALLAST WITH FILAMENT DETECTION
Document Type and Number:
WIPO Patent Application WO2004034740
Kind Code:
A3
Abstract:
A fluorescent lamp electronic ballast for use with fluorescent lamps (10) of the preheat or heated filament type is provided. The electronic ballast includes a multiple output DC to DC converter (12) with a primary winding and a plurality of secondary windings for connecting to a plurality of lamp filaments. Each secondary winding is connected to a lamp filament through a diode/capacitor combination with a current transformer primary located in a high frequency loop. A sensing circuit (18) is connected to a current transformer secondary. A controller (16) is connected to the sensing circuit (18) and controls the filament power supply. Advantages include the ability to predict lamp end of life, detect disconnected filaments and other problems that appear as an open circuit such as loose or misinstalled lamps and prevent arcing, detect smoldering of a heavily carbonized lamp holder, or detect short circuits.
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Inventors:
NEMIROW ARTHUR T (US)
SEARS STORM S (US)
SEARS STORM S (US)
Application Number:
PCT/US2003/030039
Publication Date:
July 15, 2004
Filing Date:
September 25, 2003
Export Citation:
Assignee:
BRUCE IND INC (US)
NEMIROW ARTHUR T (US)
SEARS STORM S (US)
NEMIROW ARTHUR T (US)
SEARS STORM S (US)
International Classes:
H05B41/298; (IPC1-7): H05B37/02
Foreign References:
| US6366032B1 | 2002-04-02 | |||
| US6348769B1 | 2002-02-19 | |||
| US6339299B1 | 2002-01-15 | |||
| US6243017B1 | 2001-06-05 | |||
| US5612595A | 1997-03-18 |
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