Control unit for fluorescent tube

摘要

A current measuring unit (10) is provided, which is connected to the prim. winding (11) of the transformer. The transformer sec. winding (13) supplies the fluorescent tube (1). A bridge rectifier (17) opposite the sec. winding is connected between the start-preheating electrodes (2, 3) of the fluorescent tube (1). An auxiliary transistor (16) is supplied by the rectifier (17). An ignition synchronising unit (14) is supplied by the rectifier (17), receives the control signal of the main transistor (5) at an input (24), from the modulation unit (4). Also so controls the auxiliary transistor (16) in such a manner, across an output (15). That the blocking of the auxiliary transistor, synchronous to the blocking of the main transistor (5) by the modulation unit (4).