| 摘要 |
PURPOSE:To improve the efficiency of an inverter device by providing the tertiary coil, in which the collector current of a main transistor is flowed, in a base driving transformer to perform a positive feedback, thereby increasing the reverse base bias of the main transistor. CONSTITUTION:A discharge lamp L is fired by a separately-excited inverter 4 which has main transistors Tr1, Tr2 and an output transformer T0. Tertiary coils N3 are provided in addition to the primary and secondary coils N1, N2 in transformers PT1, PT2 for driving the base, the voltage N2 is added to the base of the Tr1 via a differentiator 13 which has a collector condenser C3 and a resistor R10, and the collector is connected to the tertiary coil N3, thereby performing the positive feedback. Accordingly, the output by the collector current is applied to the coil N2, thereby increasing the effect of the differentiator 13, and the collector current can be abruptly turned OFF, thereby improving the efficiency by simplifying the base drive circuit. |
