| 摘要 |
PURPOSE:To prevent the generation of abnormal voltages at the time of light loads, by providing a current control means which detects only a corona discharge current and controls it at a constant value and a voltage control means which detects an output voltage and maintains it at a constant value. CONSTITUTION:At the normal operation, the output voltage of a voltage detecting circuit 30 is larger than the output voltage of a current detecting circuit 31; The output signal from a differential amplifier DA2 is outputted to a pulse width control device 33 via a diode 4. The corona discharge current flowing from corona discharge wire 26 to a charging member 29 is controlled at a constant value. Then the discharge condition is varied, the output voltage of a voltage increasing rectifier circuit 24 is increased, and the output voltage of the voltage detecting circuit 30 is increased. The output signal of a differential amplifier DA, is inputted to the pulse width control device 33 via a diode D3, and the output voltage of the voltage increasing circuit 24 is controlled at a constant value. |
