| 摘要 |
PROBLEM TO BE SOLVED: To inexpensively adjust the constant-voltage characteristic of a high- voltage power unit which supplies a potential to the photoreceptor, etc., of an electrophotographic device with accuracy without worsening the constant- current accuracy of the unit. SOLUTION: A high-voltage power unit is constituted in such a way that a current detecting resistor 9 is connected between the low-potential side of the secondary winding 4 of a high-voltage transformer 2 and a first reference power source 10 or an equivalent stable potential and a voltage detecting resistor which is constituted by connecting first and second resistors 11 and 13 which divide the output voltage of the unit in series is connected to an output section (a) and the low-potential side of the winding 4. Then the voltage generated in the voltage detecting resistor is compared with a second reference power source 14 by means of an error amplifier 15, and the output of the amplifier 15 and the low-potential side of the winding 4 are connected to each other through an impedance element 16, so that the synthesized voltage of the voltage generated from the output of the amplifier 15 and the voltage generated from the current detecting resistor 9 may be fed back to the primary side of the transformer 2.
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