| 摘要 |
PURPOSE: To detect speed accurately by canceling a signal generated by an electromagnetic field while maintaining the signal generated by the surrounding electromagnetic field generated from a generator and a modulated magnetic field. CONSTITUTION: Since a 400 Hz power is generated for supplying power from a generator regardless of the rotary speed of an input shaft 32, an electromagnetic field 21 is generated at the surrounding. When the frequency of the electromagnetic field 21 approaches a frequency for passing iron lobes 26-28 while detecting the iron lobes 26-28, a distorted signal is generated by the beating of the two magnetic fields 20 and 21. On the other hand, an MPU coil 15 and a search coil 19 are arranged electrically oppositely and is essentially made parallel with the wave front of the electromagnetic field 21, the disturbance of the signal of a pick-up circuit 10 can be eliminated. |
