| 摘要 |
PURPOSE:To better the starting performance of a discharge lamp by applying a power supply output voltage to the primary winding of a transformer whose secondary winding functions as a current limiting obstruction, and generating a voltage in the secondary winding so as to boost the voltage to be supplied to the discharge lamp in its start. CONSTITUTION:The primary winding of a transformer 12 is connected to the secondary winding of a transformer 22 in parallel so that the output voltage of a constant current push-pull inverter circuit 17 which is generated in the secondary winding of the transformer 22 is applied to both sides of the primary winding of the transformer 12. Then not only the output voltage of the constant current push-pull inverter circuit 17 divided in accordance with the impedance that the secondary winding of the transformer 12 originally has, but also a voltage which is boosted in accordance with the turn ratio of the primary and the secondary winding of the transformer 12 are superimposed on the secondary winding of the transformer 12. Thus, the relative output voltage of a power supply unit 11 is boosted and supplied to a discharge lamp 14 during its start so that a shift from glow discharge to arc discharge can be performed smoothly and stable lighting can be facilitated. |
