| 摘要 |
PURPOSE:To improve the stability at starting time by turning OFF the output of a voltage regulator of the primary side on the basis of the voltage of the secondary side power source and driving a photoswitching element only by the secondary side power. CONSTITUTION:An input switch 2 is closed to apply the primary high voltage DC power source 1 to a voltage regulator 24, and a photoswitching element 11 is driven by a high frequency signal through a diode 30 from an IC5 for driving a transistor. As a result, the secondary DC voltage E2 is applied to a load 17 through a high frequency transformer 13 and a rectifying diode 14. In this case, the secondary voltage E2 is used as a drive power of the controller of the element 11. Thus, the voltage E2 is stabilized to a voltage E3. The difference between the actual secondary voltage E2 through the IC21 and a reference voltage is detected to vary the ON/OFF duty of a transistor 22, and the element 11 is driven by a light emitting diode 12. Further, after ordinarily operated, the IC5 is de-energized. |
