| 摘要 |
PURPOSE:To obtain a stable position detection signal by obtaining a signal of 90 deg. phase delay of 2-phases by a voltage between the phases U and V and between the phases W and V of stator windings and analog calculating the voltage between the phases W and U under 3-phase equilibrium condition. CONSTITUTION:A phase detector 6 detects the position of a rotor 5b from the induced voltage generated in a stator winding 5a, and outputs a position detection signal for controlling the transistors of an inverter 4. This detector 6 has a phase shifter 7 having the first and second phase shifting units 7a, 7b for producing a 90 deg. phase delay approx. sinusoidal output by the voltage between the phases U and V and between the phases W and V of the winding 5a, a buffer circuit 9 having the first and second buffer units 9a, 9b, a phase inverter 10, an addition inverter 11, and a comparator 12 for comparing the outputs of the inverter 11 with the outputs of the buffer units 9a, 9b and the phase inverter 10. |
