| 摘要 |
PURPOSE:To simplify the structure of a motor by a method wherein the condition of an exciting coil is detected from energy, stored in a plurality of exciting coils during restricting period of time, as an electric characteristic and a rotor is rotated into a predetermined direction during successive starting period. CONSTITUTION:When a power source is thrown, a conduction switching circuit 23 puts transistors Q1-Q6 ON/OFF to conduct phase currents I-Iw by a phase switching circuit 25 whereby energy is stored in coils Lu-Lw. After a predetermined time, the conduction switching circuit 23 nullifies the conduction and discharges the energy whereby capacitors C1-C3 are charged by both terminal voltages of resistors R1-R3. The charge of the capacitors C1-C3 becomes values affected by the effective inductances of respective coils while the outputs of comparators CP1-CP3 detect the direction of rotation through detectors 29 to indicate them in a phase switching circuit 25. When the restricting period is finished, the motor is started and accelerated whereby the rotation of the motor is shifted into a rated rotation. |
