| 摘要 |
PURPOSE:To stabilize output despite varying voltage supplied by furnishing a phase adjusting means, changing the generated phase of a high frequency power supply for lighting a lamp, and by adjusting the oscillation start timing. CONSTITUTION:AC power is whole-wave rectified by a rectifier 1 to supply power to a starter circuit and an inverter circuit. The size of the output voltage from the rectifier 1 is sensed, and corresponding control signals are produced. On the basis of these control signals, the oscillation timing of a high frequency power supply is adjusted in each phase of output from rectifier 1. The output voltage of the rectifier 1 is divided by resistances 23, 25 to provide a gate voltage for a PUT 29. Also, voltage divided by another resistance 21 and a capacitor 27 is impressed on the anode of the PUT 29. When the anode voltage becomes higher than the grid voltage, an inverter circuit begins oscillating. When a phase adjusting means varies the generated phase of high frequency power supply, the point of time when the inverter circuit begins transmitting signals, is changed, and thus stable output is obtained despite varying voltage supplied. |
