EP 0020493 B1 19860312 - FLUORESCENT LAMP LIGHTING SYSTEM
Title (en)
FLUORESCENT LAMP LIGHTING SYSTEM
Publication
Application
Priority
US 94584278 A 19780926
Abstract (en)
[origin: WO8000776A1] An energy conserving lighting system wherein a plurality of fluorescent lamps (L1", L2") are powered by a poorly regulated voltage supply which provides a decreasing supply voltage with increasing arc current so as to generally match the volt-ampere characteristics of the lamps. A transistor ballast and control circuit connected in the arc current path controls the arc current, and hence the light output, in accordance with the total ambient light, i.e., the light produced by the lamps together with whatever further light, is produced by other sources such as daylight. In another embodiment, a transistor ballast is utilized in combination with an inductive ballast (1001). The transistor ballast provides current control over a wide dynamic range up to a design current maximum at which maximum the transistor (60""") is saturated and the inductive ballast takes over the current limiting function. An operational amplifier (116) is preferably connected in the base biasing circuit of the control transistor of the transistor ballast. In an embodiment wherein two sets of lamps with separate inductive ballasts (100", 142) are provided, the arc currents for the two ballasts are scaled or matched to provide the desired light output.
IPC 1-7
IPC 8 full level
H05B 41/392 (2006.01)
CPC (source: EP)
H05B 41/392 (2013.01)
Designated contracting state (EPC)
DE GB NL SE
DOCDB simple family (publication)
WO 8000776 A1 19800417; CA 1128605 A 19820727; DE 2967585 D1 19860417; EP 0020493 A1 19810107; EP 0020493 A4 19820422; EP 0020493 B1 19860312; FR 2443183 A2 19800627; FR 2443183 B2 19840615; JP S5598500 A 19800726; MX 149353 A 19831026
DOCDB simple family (application)
US 7900785 W 19790926; CA 320173 A 19790124; DE 2967585 T 19790926; EP 79901332 A 19800422; FR 7923905 A 19790926; JP 12373779 A 19790926; MX 17938979 A 19790925