| 摘要 |
PURPOSE:To reduce the number of connections between a sensor section and a control circuit, by fitting sensor coils on a part of a stator of ferromagnetic material, and by permitting current to flow in the coils to detect the impedance of the sensor coils and to detect the rotational position of a rotor. CONSTITUTION:By transistors(Tr) 30-32, three-phase driving coils 1a, 2a, 3a are switched in order. By a Tr 33, current to three phases is limited, and by a Tr 34, the current in sensor coils is controlled. The collectors of the respective Trs are connected to the terminals 7a-10a and 14 of a control circuit 13a, and by a control circuit 37, the Trs 30-34 are controlled. Adequate voltage is applied between terminals 38-45, and the Trs 30-34 are controlled, and pulse voltage is applied to sensor coils 4a, 5a, 6a in order, and the maximum value among the resultant currents is detected. When current is permitted to flow in driving coils corresponding to the sensor coils of the current value which is equal to or less than a specified value, a rotor is rotated. |
