Fluorescent tube operating circuit using AC and rectangular voltages - has AC voltage applied to transformer primary, whose secondary is coupled to fluorescent tube and parallel switch

摘要

In the operation a HF AC voltage and a LF rectangular voltage are generated with adjustable pulse width for periodical blocking and release of the AC voltage at the fluorescent tube. The rectangular voltage is generated from the AC voltage by frequency division and following pulse width modulation. The circuit contains a transformer (3), to whose primary side is applied the AC voltage. To its secondary side is coupled a parallel connection of the fluorescent tube (7) and a switch (8), controllable by the rectangular voltage, via a coil (6). ADVANTAGE - Wide adjusting range, with reliable fluorescent tube operation within entire adjusting range.