| 摘要 |
PURPOSE:To obtain a small-sized electromagnetic rotating machine, cost of which is reduced, by making the AM component of the change of magnetic field intensity generated by one of two electromagnetic coupling elements installed to the rotor side and the stator side, affecting to the other, to 1ppr. CONSTITUTION:A change by the revolution of a rotor 4 in a magnetic field generated by an FG magnet 2 is detected by a generating wire element 7a. The output signal of the generating wire element 7a generates sixty pulses per one revolution (60ppr) because one hundred and twenty magnetizing inversion is executed to the magnet 2. The sixty pulses are modulated by a sine wave of 1ppr. The AM modulation signal is half-wave rectified, and sample-and-hold processed, thus acquiring a rotational-position detecting signal. That is, magnetic field intensity between two electromagnetic coupling elements is AM-modulated by 1ppr, and a rotational position signal can be formed from the modulation component, thus omitting a rotary magnet exclusive for a conventional index and an element for detecting a rotational position. |
