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1. (WO2018221628) MOTOR CURRENT CONTROL DEVICE AND MOTOR CURRENT CONTROL METHOD

Pub. No.:    WO/2018/221628    International Application No.:    PCT/JP2018/020869
Publication Date: Fri Dec 07 00:59:59 CET 2018 International Filing Date: Thu May 31 01:59:59 CEST 2018
IPC: H02P 8/22
Applicants: MINEBEA MITSUMI INC.
ミネベアミツミ株式会社
Inventors: YAMAZAKI Kei
山▲崎▼ 圭
SEKI Tetsuya
関 徹也
MIYAJI Shigeki
宮地 茂樹
Title: MOTOR CURRENT CONTROL DEVICE AND MOTOR CURRENT CONTROL METHOD
Abstract:
The present invention suppresses high-frequency noise in micro step driving of a stepping motor. A motor control device (100) comprises: an H bridge circuit (20); and a control means that drives a switching element of the H bridge circuit (20) using a PWM signal and sets a motor coil to a charging mode, a high-speed attenuation mode, or a low-speed attenuation mode. The control means switches the H bridge circuit (20) to the charging mode and then to the low-speed attenuation mode every PWM period in a range from an electrical angle at which a reference current value begins to fall to an electrical angle of +52°. After exceeding +52°, in a range up to +90° where the reference current value begins to rise, in each PWM period, the control means switches the H bridge circuit (20) to the charging mode and then, if a motor current exceeds the reference current value, switches the H bridge circuit (20) to the high-speed attenuation mode and then to the low-speed attenuation mode.