EP 0059064 B1 19851002 - LAMP DRIVER CIRCUITS
Title (en)
LAMP DRIVER CIRCUITS
Publication
Application
Priority
GB 8105551 A 19810221
Abstract (en)
[origin: EP0059064A1] The invention provides a lamp driver circuit for discharge lamps, in particular fluorescent lamps. An inverter (12) receiving DC provides a high frequency AC output. A resonant circuit includes a capacitor (C25) connected across the lamp (13) and a ballast inductor (L2) in series with them. A control arrangement (15, 16) causes the inverter (12) to operate at a frequency above the resonant frequency of the lamp when initially switched on. It is then caused to sweep down in frequency towards the resonance frequency so that the lamp strikes as a result of the magnified voltage applied to it. After the lamp has struck the frequency drops to a suitable running frequency. If the lamp strikes a circuit (L25, 201, 17) controls the frequency to limit the lamp voltage. Another circuit (DCT1, 203, P1, 17 min ) controls the lamp frequency for dimming purposes. The circuit when operative at the initial higher frequency provides heating current through the filament before the lamp strikes since the capacitor (C25) shunts the lamp at such frequency.
IPC 1-7
IPC 8 full level
H05B 41/298 (2006.01); H05B 41/392 (2006.01)
CPC (source: EP)
H05B 41/2981 (2013.01); H05B 41/392 (2013.01)
Citation (examination)
- JP S55126998 A 19801001 - NIPPON ELECTRIC CO
- JP S55128298 A 19801003 - NIPPON ELECTRIC CO
Designated contracting state (EPC)
DE FR GB NL SE
DOCDB simple family (publication)
EP 0059064 A1 19820901; EP 0059064 B1 19851002; DE 3266600 D1 19851107
DOCDB simple family (application)
EP 82300787 A 19820216; DE 3266600 T 19820216