Patent ID: 9647586
Date: 2017-05-09
CPC Classifications: H02P

Claim:
1. A signal amplifier for a phase detector generating a phase information signal, based on plural sensor signals having amplitude levels in accordance with a rotational position of a rotor of a motor having a plural-phase coil to detect the rotational position thereof, comprising: an amplitude detector configured to detect or estimate, for each sensor signal amongst the plural sensor signals, a peak level of the sensor signal, for each signal amplification section amongst plural signal amplification sections into which a phase of the sensor signal is divided by a predetermined number in accordance with a number of poles of the motor, based on a signal level of the sensor signal, to produce a result signal; and a signal amplification unit configured to adjust an amplitude level of each of the sensor signals, for said each signal amplification section amongst the signal amplification sections, such that the detected or estimated peak level of the sensor signal for said each signal amplification section amongst the signal amplification sections has a specified amplitude level corresponding to the signal amplification section.