| 摘要 |
PURPOSE:To almost equally generate an output current of rated load even when connected any of a neon tube or an argon tube by providing a means for switching an output level in accordance with a kind of the connected discharge tube. CONSTITUTION:When a power supply is closed to generate predetermined voltage across both ends of a capacitor 35, a controlling IC37 is oscillated to differentiate its output by a pulse transformer 42, turn on an FET27 by a riseup pulse, flow a current via the FET27, low voltage winding 32 and a capacitor 26, next to turn on an FET28 by a trailing edge pulse of an oscillation output, and to flow a current through a capacitor 25, winding 32 and the FET 28 boosted to apply alternating voltage to a discharge tube 47. When turned on a switch 48 of an output switching means switched in accordance with a neon tube or argon tube, an oscillating frequency of the controlling IC37 is increased, and by this amount, impedance of a high voltage winding 46 of a booster transformer is increased, to reduce a short-circuit current in the winding. The neon tube, when lighted in this condition, is brightly lighted. |
