EP 0361665 A3 19900530 - POWER CIRCUIT
Title (en)
POWER CIRCUIT
Publication
Application
Priority
GB 8822781 A 19880928
Abstract (en)
[origin: EP0361665A2] A power circuit for a low pressure sodium lamp utilises a high frequency oscillator which delivers a constant current to the lamp and which has a frequency of oscillation which is largely independent of variations in the impedance of the lamp. Sodium lamps have negative temperature-resistance coefficient, and the effect of the circuit is to counteract any tendency for the current taken by the lamp to increase as it heats up during operation. An additional inductance is provided between the oscillator itself and the lamp acts to stabilise the frequency of oscillation and hold constant the current delivered to the lamp.
IPC 1-7
IPC 8 full level
H05B 41/292 (2006.01)
CPC (source: EP)
H05B 41/2925 (2013.01)
Citation (search report)
- [A] GB 2178607 A 19870211 - MATSUSHITA ELECTRIC WORKS LTD
- [A] US 4608523 A 19860826 - NILSSEN OLE K [US]
- [A] US 4358712 A 19821109 - FILGAS JR LUDOVIC S, et al
- [A] US 4554487 A 19851119 - NILSSEN OLE K [US]
- [A] GB 2057795 A 19810401 - ELECO LTD
Designated contracting state (EPC)
DE NL
DOCDB simple family (publication)
EP 0361665 A2 19900404; EP 0361665 A3 19900530; GB 2223367 A 19900404; GB 8822781 D0 19881102; GB 8918671 D0 19890927
DOCDB simple family (application)
EP 89308322 A 19890816; GB 8822781 A 19880928; GB 8918671 A 19890816