| 摘要 |
PURPOSE:To make an inverter transformer light and compact by lighting a discharge lamp by operating a half wave double voltage circuit at the start, stopping the operation of the half wave double voltage circuit, and applying voltage from an inverter lighting circuit after lighting. CONSTITUTION:At the start, an inverter lighting circuit 16 is operated by a d.c. power source 11 and voltage is applied to a discharge lamp 18 from a secondary coiled wire 14a of an inverter transformer 14 through a capacitor 17 for a ballast. At the time, since the voltage applied to the discharge lamp 18 is relatively high, a nonlinear-type switching device 22 is turned on and a diode 23 is connected in a circuit. Owing to this, half wave double voltage function works on the capacitor 17 and the diode 23 and the voltage becomes sufficient to start and light the discharge lamp 18. When the discharge lamp 18 is turned on, the voltage across the discharge lamp 18 drops, so that the device 22 is turned off and the lighting is kept only by the output of the inverter lighting circuit 16. Consequently, an inverter transformer can be made light and compact. |
