US 9,813,002 B2
Motor controller and turbo-molecular pump
Nobuhiko Moriyama, Kyoto (JP)
Assigned to SHIMADZU CORPORATION, Kyoto (JP)
Filed by SHIMADZU CORPORATION, Kyoto (JP)
Filed on Aug. 12, 2014, as Appl. No. 14/457,216.
Claims priority of application No. 2013-179613 (JP), filed on Aug. 30, 2013.
Prior Publication US 2015/0064024 A1, Mar. 5, 2015
Int. Cl. F04D 19/04 (2006.01); H02P 7/06 (2006.01); F04D 27/02 (2006.01); H02P 21/04 (2006.01); H02P 21/18 (2016.01)
CPC H02P 7/06 (2013.01) [F04D 19/042 (2013.01); F04D 27/0261 (2013.01); H02P 21/04 (2013.01); H02P 21/18 (2016.02); H02P 2203/03 (2013.01)] 4 Claims
OG exemplary drawing
 
1. A motor controller comprising:
a rotation angle estimator estimating and computing a rotation angle of a motor repeatedly based on the current and voltage of the motor without using a motor rotation angle detector;
a speed calculator calculating a period of a signal waveform of the rotation angle that is repeatedly estimated and calculated by the rotation angle estimator and for calculating an actual rotational speed of the motor by taking the inverse of the period of the signal waveform of the rotation angle;
a drive signal generator generating a drive signal to drive and control the motor based on at least a deviation between the actual rotational speed and a target rotational speed and the rotation angle; and
a switching circuit that is switched based on the drive signal to provide drive power to the motor,
wherein the speed calculator comprises a binarization section binarizing the signal of the rotation angle obtained by the rotation angle estimator, and
a calculator for calculating the period based on the binary signal obtained by the binarization section.