EP 0496040 B1 19941228 - AC Ballast for discharge lamps.
Title (en)
AC Ballast for discharge lamps.
Title (de)
Wechselspannungs-Vorschaltgerät für elektrische Entladungslampen.
Title (fr)
Ballast alternatif pour lampes à décharge.
Publication
Application
Priority
DE 4101980 A 19910124
Abstract (en)
[origin: EP0496040A1] The ballast has two switches (S1, S2) which are connected to the AC supply in series and can be operated inversely with respect to one another. A series circuit consisting of an inductor (L) and a discharge lamp (EL) is connected to this switch arrangement. The discharge lamp (EL) is shorted out by a third switch (S3). As long as the amplitude of the supply voltage (UN) is less than a limiting value, the third switch (S3) is switched on and off a plurality of times within one half cycle of the supply voltage, with the first switch (S1) turned on. In this way, it is achieved that, in those regions of the half cycle in which the lamp would normally be extinguished because the supply voltage is not adequate, a sufficiently high voltage for lamp operation is made available by the inductor (L). The power transferred during one half cycle of the lamp can be varied corresponding to a desired power curve by varying the duty cycle of the pulses. <IMAGE>
IPC 1-7
IPC 8 full level
H05B 41/16 (2006.01); H05B 41/298 (2006.01)
CPC (source: EP)
H05B 41/2988 (2013.01)
Designated contracting state (EPC)
AT CH DE FR GB IT LI NL
DOCDB simple family (publication)
EP 0496040 A1 19920729; EP 0496040 B1 19941228; AT E116509 T1 19950115; DE 4101980 A1 19920806; DE 59104073 D1 19950209
DOCDB simple family (application)
EP 91117443 A 19911012; AT 91117443 T 19911012; DE 4101980 A 19910124; DE 59104073 T 19911012