| 摘要 |
PURPOSE:To obtain a rotation detecting apparatus, which can obtain the rotation speed data and the position data signal in high resolution without using a frequency generator having a fine magnetizing pitch. CONSTITUTION:A sine-wave voltage (sintheta) and a cosine-wave voltage (costheta) are obtained with a magnetism-sensitive element 2. The carrier wave signal V0=sin(2pi/T)t, which is obtained from an oscillator 5, is supplied to the magnetism-sensitive element 2. Among the output voltages, which are obtained by the multiplication in the magnetism sensitive element 2, the voltage of V3= sintheta.cos(2pi/T)t is obtained by delaying the phase of the carrier component of V1=sintheta.sin(2pi/T)t by 90 degrees with a phase shifting circuit 6. The value V3 and V2=costheta.sin(2pi/T)t are added with an adder 7, and V4=sin(2pit/T+theta) is obtained. The phase difference between V4 and the carrier wave signal V0 is detected with a phase comparing circuit 8, and the value of theta (rotating position data) is obtained. |
