AC VOLTAGE DETECTOR, IMAGE FORMING DEVICE, AND INDUSTRIAL MACHINE

摘要

To provide a new technique for detecting an AC voltage on the secondary side.SOLUTION: An AC voltage detector (AC voltage detection unit 40) comprises: a rectification circuit (AC voltage rectification/step-down circuit 41) for rectifying an AC voltage outputted from an AC power supply 15; a voltage pulse conversion circuit 43 for converting a rectified voltage Vac having been rectified by the rectification circuit into a first pulse signal Vp1 of a shorter period than half the period of the AC voltage; a pulse transfer circuit 44 for converting the first pulse signal Vp1 into a physical signal separate from electricity and converting the physical signal into a second pulse signal Vp2 that is an electric signal, thereby transferring the signal while electrically insulating it; and a control unit 100 to which the second pulse signal Vp2 is inputted. The control unit 100 calculates the voltage value of the AC voltage from the characteristic value of the second pulse signal Vp2.SELECTED DRAWING: Figure 3