PURPOSE: To minimize the capacity of a voltage dividing capacitor by providing series-connected switching elements for controlling the application of voltage to the primary winding of a high voltage transformer, a plurality of voltage dividing capacitors, and a resonance capacitor.
CONSTITUTION: Switching elements 5a, 5b connected in series to each other are connected in series to the primary winding 4a of a booster transformer 4. Further, a plurality of voltage dividing capacitors 14a, 14b are connected in parallel to each of the elements 5a, 5b. A resonance capacitor 3 is connected in parallel to the primary winding 4a of the transformer 4. When the elements 5a, 5b are OFF, the resonance circuit of the capacitor 3 and the winding 4a is resonated, and the voltage V1 of the winding 4a is changed to a sinusoidal waveform. At this time, the voltages applied to the individual elements 5a, 5b are the voltages divided by the capacitors 14a, 14b. Thus, since the capacities of the capacitors 14a, 14b can be sufficiently smaller than that of the capacitor 3, an inexpensive small-size ceramic capacitor can be used.
YUASA FUMIO
OZAWA SEI
