| 摘要 |
PURPOSE:To detect a position of a rotor with lower comsumption of power by deciding the position of the rotor through taking out bouncing voltage generated with exciting current for the difference in the inductance of an exciting coil, which is generated in accordance with the position where the rotor stops. CONSTITUTION:To an exciting coil 17 of a step motor, detecting current is applied through changing over from a condition (a), in which switching elements 32 and 33 are turned on, into that (b), in which the switching elements 30 and 33 are turned on. Then, through turning the switching elements 30 and 31 off and the switching elements 32 and 36 on (c), bouncing voltage proportional to the current which has flowed through the coil 17 is generated along a resistor 37. Since the inductance of the coil 17 changes in accordance with a position of a rotor, said bouncing voltage also changes in accordance with the position of the rotor and is able to detect the position of the rotor. |
