| 摘要 |
<p>PURPOSE:To prevent the occurrence of the abnormal state caused by open circuit of a resonance capacitor or the like due to a failure of work, a broken pattern on a board, or the like. CONSTITUTION:A horizontal drive pulse is supplied to the gate of a MOS field- effect transistor FET 41 as a high voltage output transistor TR. The source of the FET 41 is grounded, and the drain is connected to a power terminal 44 through a low voltage coil 42a of a flyback transformer 42 and a filter 43. One end of a high voltage coil 42b of the transformer 42 is connected to a high voltage rectifier circuit 45, and the other end is connected to one end of the low voltage coil 42a. The resonance capacitor is not connected to the primary side of the transformer 42, and only the inductance of the low voltage coil 42a and the internal stray capacitance constitute a resonance circuit. A boosted resonance pulse voltage is obtained in the high voltage coil 42b, and a high voltage HV is obtained by the rectifier circuit 45. It is unnecessary to mount the resonance capacitor on the circuit board, and the abnormal state caused by the open circuit of the resonance capacitor or the like due to a failure of work cannot occur.</p> |
