| 摘要 |
PURPOSE:To resolve unstability of arc and make a high-voltage electric discharge lamp-lighting device compact and light by turning on a power supply to make a semiconductor switch in on/off operation at a high frequency by a first high frequency-oscillating circuit with repeating the operation alternatively for a constant duration by a low frequency-oscillating circuit. CONSTITUTION:An AND circuit 20 is opened is opened and a transistor 12 is turned on when the output of a low frequency-oscillating circuit 22 and that of a first high frequency-oscillating circuit 19 are both at H level. A transistor 4 is thus turned on through a transformer 10 and a resistor 8 and is turned off when the output of the first high frequency-oscillating circuit 19 is turned into L level. Accordingly, when the output of the low frequency-oscillating circuit 22 is at H level, the transistor 4 is turned on/off at a high frequency by the first high frequency-oscillating circuit 19. A transistor 5 is still off at this time. When the output of the low frequency-oscillating circuit 22 is at L level. The transistor 5 is turned on/off at a high frequency by the first high frequency-oscillating circuit 19. The transistor 4 is still off at this time. Accordingly, the transistors 4 and 5 are turned on/off at a high frequency for a constant duration at a low frequency. |
