| 摘要 |
PURPOSE:To electrically insulate between a low voltage side and a high voltage side by extracting the current level supplied to an electrostatic application unit, and controlling a regulator at a low voltage input side through a photocoupler driven by an auxiliary power source. CONSTITUTION:The output of a chopper type switch regulator 15 is applied to an oscillator 16, and a high voltage is applied to the electrostatic application unit of an electrostatic copying machine through a high voltage transformer 17 and a high voltage rectifier 21. The output current is detected by a detector 22, a photocoupler light emitting unit 27 is operated through an amplifier 24 using an auxiliary coil 20 applied to the secondary side of the transformer 17 as a power source and a backup circuit 28, a light is received by a photoreceptor 33, and the regulator 15 is controlled. Accordingly, the low and high voltage sides are effectively insulated by introducing the photocoupler with the coil 20 provided in the transformer 17 to linearly control from high to low sides. |
