CIRCUIT ARRANGEMENT FOR THE IGNITION AND OPERATION OF ONE OR A NUMBER OF LOW VOLTAGE FLUORESCENT LAMPS CONNECTED IN SERIES

摘要

1454074 Discharge lamp circuits F KNOBEL ELEKTRO-APPARATEBAU AG 28 Feb 1975 [28 March 1974] 8581/75 Heading H2H Apparatus for starting and operating one or more series connected filamentary electrode low voltage discharge lamps 1, 2 comprises a transformer, preferably an autotransformer, having a primary 5 connected to an a.c. supply 50, a secondary winding 4, and one or more heating windings 7-9, the heating windings being connected with the electrodes 1a-2b of the lamps, and further comprises a positive resistance characteristic thermistor 10 or 10SP1/SP connected in parallel with at least part of the secondary winding 4 of the transformer. The transformer is designed to produce sufficient voltage to start the lamp but is prevented from applying this voltage to the lamp electrodes for a period after energisation determined by the characteristic of the thermistor to allow sufficient preheating of the electrodes of the lamps.