The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 05, 2022
Filed:
Sep. 12, 2019
Hitachi Astemo, Ltd., Hitachinaka, JP;
Hikaru Miura, Hitachinaka, JP;
Tomonori Kanai, Hitachinaka, JP;
Akihiro Machida, Hitachinaka, JP;
Tatsumi Yamauchi, Hitachinaka, JP;
Hitachi Astemo, Ltd., Hitachinaka, JP;
Abstract
Provided is an electromagnetic switch control device capable of stabilizing a contact pressure by predicting a near-future value of an operation coil current and performing control such that the near-future value does not fall below a holding current threshold value by a control unit. An electromagnetic switch control deviceopens and closesby an electromagnetic force corresponding to energization of operation coilsand, and includes PWM control unitstothat perform PWM pulse width modulation control of a current value A flowing through the operation coilsand. The PWM control unitstoestimate the near-future predicted current value flowing through the operation coilsandby using a terminal voltage V of the operation coilsand, and perform PWM control based on the estimated current value. The predicted current value Y is estimated by using an impedance Z of the operation coilsand. The impedance is a variable obtained by current values Aand Aand terminal voltages Vand Vof the operation coilsand, and a constant approximated over a predetermined period from a latest past to a present time is used. The impedance is updated for each predetermined period.