Abstract: An electric power supply control device comprises a first converter, at least one second converter, and an electrical voltage control unit. The second converter can work in intermittent oscillation, and converts outputting electrical voltage from the first converter. The electrical voltage control unit controls the outputting electrical voltage of the first converter, so that the outputting electrical voltage is equal to or less than a minimum value of upper limits of operating electrical voltage of the second converter, and is more than or equal to a maximum value of lower limits of operating electrical voltage of the second converter, and at least one of the second converter performs low electric power behavior.

Abstract: An electric power supply control device comprises a first converter, at least one second converter, and an electrical voltage control unit. The second converter can work in intermittent oscillation, and converts outputting electrical voltage from the first converter. The electrical voltage control unit controls the outputting electrical voltage of the first converter, so that the outputting electrical voltage is equal to or less than a minimum value of upper limits of operating electrical voltage of the second converter, and is more than or equal to a maximum value of lower limits of operating electrical voltage of the second converter, and at least one of the second converter performs low electric power behavior.

Abstract: A power supply unit selects one of drive power provided from an AC/DC conversion unit and that provided from a separation unit and outputs the selected drive power to a control unit and a transmission and reception unit continuously. If the AC/DC conversion unit and the separation unit both supply their respective drive powers, the drive power that has a higher voltage value, i.e., the first drive power, is selectively output. When the first drive power supplied is stopped, a diode transitions from the on state to the off state and a diode transitions from the off state to the on state. As a result the second drive power is selectively output.

Abstract: A drive control mechanism for an image reader having a controller, to control a drive current impressed to a connected stepping motor such that the impression of the drive current is carried out in a prescribed number of steps, and a changer, to change a largest value of a drive current in response to a scanning speed of a reading device of the image reader. Consequently, smooth rotation with little torque ripple may be obtained through microstep driving, and by changing a largest drive current, control of a drive torque becomes easier, thus making it possible to maintain an even balance between load torque and drive vibration when a high-torque motor is used to eliminate slider vibration.