| 摘要 |
PURPOSE:To obtain a high voltage power source circuit having high reliability with good circuit efficiency without unstable oscillation state by driving a switching transistor with the output of an oscillator which varies the oscillating frequency in response to the primary side voltage of a transformer. CONSTITUTION:A level detecting circuit LD detects the output level of the primary voltage E0 of a transformer T1, and outputs a signal responsive to the level. A switching transistor TR3 is driven by the output of an oscillator OC controlled in the oscillating frequency with the output of the detector LD. In this manner, the circuit effeciency is kept always good even if the secondary side high voltage output is any of maximum, minimum and medium, and high voltage power source circuit of high reliability can be performed without unstable oscillation state. |
