| 摘要 |
PURPOSE:To improve starting characteristic by counting the time between zero-crossing points of a counter-electromotive forces induced in stator windings, and determining the conduction phases of the windings to be conducted next based on the counted values. CONSTITUTION:A pulse delay means 2 counts a period (n) of a pulse train indicating a zero-crossing point of 3-phase counter-electromotive forces inputted from a counter-electromotive force detecting means 1, and delays an input pulse, for example, by about 1/2 time of the counted period. A logic pulse generating means 3 divides in frequency a pulse (z) outputted from the means 2, and outputs pulses of 6 phases of the same frequency as that of the counter- electromotive force induced in stator windings 11-13. 6-phase pulse signals generated from the means 3 become position signals of a rotor, input to a stator winding power supply means 4, which sequentially supplies driving currents to the windings 11-13 in both directions in response to the rotor position signal outputted from the means 3. |
