| 摘要 |
PURPOSE:To remove generation of spike voltage when output voltage accompanied by the spike voltage produced in turning on and off a switching device exceeds a predetermined value, by operating a shock preventer to clamp voltage at a predetermined value or less. CONSTITUTION:When a transistor Tr12 is turned on by spike voltage, current flows through its collector to cut positive spike voltage. However, since this voltage is generated in the change-over of current, it provides considerable energy, impedances of a diode D13 and transistor Tr12 should be set considerably low to bypass this energy through the transistor Tr12. Then, a capacitor C12 is inserted to reduce charge current in high voltage immediately after the change-over in inverse proportion to charge voltage in the capacitor C12 so that the transistor Tr12 is shifted from the saturated region side to the active region side and then completely to the shut-off region. |
