Electronic device and method of controlling the same

Abstract

In an electronic device having a stepping motor which can be driven more quickly than in a normal driving operation without causing a significant increase in power consumption, a detecting coil control circuit is provided which controls a connection circuit serving to open and close a detecting coil that is wound coaxially with a driving coil, in such a manner that the detecting coil is opened during the period in which a quick driving pulse is supplied to the driving coil. After supplying the quick driving pulse, a driving controller controls a driving circuit so as to open the driving coil, while the driving controller closes the detecting coil so that a voltage induced in the detecting coil by an electromotive force is detected by a position detecting circuit thereby determining the position of a rotor. The chance that the driving coil and the detecting coil act as electromagnetic brakes is minimized thereby ensuring that the quick driving operation is performed with low power consumption. During the quick driving operation in which the rotor rotates at a high speed, the position of the rotor is monitored thereby ensuring that the quick driving operation is performed in a stable fashion. Additionally, the timing of the delivery of the driving pulses may be varied in response to a measured voltage.