EP 0165893 B1 19890426 - BRIGHTNESS CONTROL DEVICE FOR A FLUORESCENT LAMP
Title (en)
BRIGHTNESS CONTROL DEVICE FOR A FLUORESCENT LAMP
Publication
Application
Priority
CH 301784 A 19840621
Abstract (en)
[origin: EP0165893A2] 1. Device for controlling the brightness of fluorescent lamps by means of an adjustable phase control of each voltage half wave of a feeding alternating-current system, the current switched from the time of the phase control to the next zero transition of the voltage halfwave being supplied via a current-limiting ballast to the fluorescent lamp, the cathodes of the fluorescent lamp furthermore being continuously and uncontrolledly heated by the alternating current system, and means being provided to supply higher-frequency energy to the fluorescent lamp for its ignition, characterized by a trigger circuit (18) which can be fed by the voltage of the phasecontrolled halfwave of the system alternating voltage and a damped resonant circuit (31) which can be charged, which is connected to the trigger circuit and to which the fluorescent lamps can be connected with respect to alternating current, the damped oscillation of the resonant circuit (31) triggered by the trigger circuit having a higher frequency than the frequency of the system alternating voltage and exhibiting at the beginning an electric power which is sufficient for igniting the fluorescent lamp.
IPC 1-7
IPC 8 full level
H05B 41/392 (2006.01)
CPC (source: EP)
H05B 41/3924 (2013.01)
Designated contracting state (EPC)
AT BE CH DE FR GB IT LI LU NL SE
DOCDB simple family (publication)
EP 0165893 A2 19851227; EP 0165893 A3 19860409; EP 0165893 B1 19890426; EP 0165893 B2 19930609; AT E42663 T1 19890515; DE 3569864 D1 19890601
DOCDB simple family (application)
EP 85810080 A 19850228; AT 85810080 T 19850228; DE 3569864 T 19850228