| 摘要 |
PURPOSE:To compensate the displacement of the position of mounting of a phase detecting means for a motor by adjusting the phase of currents conducted to the motor by first and second phase-shifting means. CONSTITUTION:A motor driving circuit is constituted of operational amplifiers OP, comparators CP, a Hall element HS sensing the position of a motor, transistors T, switches SW, etc. A lag phase shifter is formed by the operational amplifiers OP4, OP6, capacitors C0, C2, etc., and a lead phase shifter is shaped by the operational amplifiers OP5, OP7, capacitors C1, C3, etc. Outputs from the comparators CP are changed over by the rotational changeover switch SW2, and each transistor T is driven by inversion. Consequently, even when the position of mounting of the Hall element HS is displaced, phase detected by a detecting means is shifted electrically according to the displacement, and can be totalled with mechanical phase. Resistors R10, R13, R16, R19 are half fixed, thus arbitrarily adjusting the quantity of phase shifting.
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