| 摘要 |
PURPOSE:To dispense with a two-phase sine wave exciting signal and to simplify a structure, by detecting the current flowing to an exciting coil and extracting the fundamental wave component of the current flowing to the exciting coil by a rectifying means and a low band-pass filter. CONSTITUTION:When a rotor 2 rotates, the magnetic resistances between the pole teeth 1a of magnetic poles 11-18 and the pole teeth 2a of a rotor 2 change in such a state that phases are shifted by 90 deg.. Therefore, the impedances of exciting coils 11a-18a wound around the magnetic poles 11-18 change and current change shifted by 90 deg. in a phase generates in the exciting coils 11a-18a and a carrier signal Sc is modulated by said current change. The modulated carrier signal is taken out as shunt voltages V1-V4 from one terminal of a shunt resistor R and the shunt voltages V1, V3 of an inverse phase among said shunt voltages are rectified through low band-pass filters 34, 35 to obtain sine waves Sa, Sb and these two-phase sine waves Sa, Sb can be used as the magnetic pole position signal of a two-phase pulse motor. |
