公开(公告)号：US20190326091A1

公开(公告)日：2019-10-24

申请号：US16387630

申请日：2019-04-18

Applicant: Ebara Corporation

Inventor： Haruka Takeuchi ,  Tomonori Ohashi ,  Ichiju Sato

IPC: H01J37/32 ,  H01F7/06 ,  H01F7/20

Abstract: An electromagnet control device includes a current value determining circuit configured to execute a second process for determining, based on a second function, a value of the current, in the case that the magnetic flux density is to be decreased from that in a first magnetization state, and a fourth process for expanding or reducing the second function by use of a first scaling ratio for transforming it to a fourth function, and determining, based on the fourth function obtained after above transformation, a value of the current, in the case that the magnetic flux density is to be decreased from that in a third magnetization state. The current value determining circuit is further configured to determine the first scaling ratio in such a manner that the second function fits measured data that are obtained in advance by decreasing the magnetic flux density from that in the third magnetization state.

公开(公告)号：US11244812B2

公开(公告)日：2022-02-08

申请号：US16387630

申请日：2019-04-18

Applicant: Ebara Corporation

Inventor： Haruka Takeuchi ,  Tomonori Ohashi ,  Ichiju Sato

IPC: H01J37/32 ,  H01F7/06 ,  H01F7/20

Abstract: An electromagnet control device includes a current value determining circuit configured to execute a second process for determining, based on a second function, a value of the current, in the case that the magnetic flux density is to be decreased from that in a first magnetization state, and a fourth process for expanding or reducing the second function by use of a first scaling ratio for transforming it to a fourth function, and determining, based on the fourth function obtained after above transformation, a value of the current, in the case that the magnetic flux density is to be decreased from that in a third magnetization state. The current value determining circuit is further configured to determine the first scaling ratio in such a manner that the second function fits measured data that are obtained in advance by decreasing the magnetic flux density from that in the third magnetization state.

公开(公告)号：US11662397B2

公开(公告)日：2023-05-30

申请号：US17659684

申请日：2022-04-19

Applicant: EBARA CORPORATION

Inventor： Haruka Takeuchi ,  Tomonori Ohashi ,  Ichiju Sato

IPC: G01R33/022 ,  G01R33/028

CPC classification number: G01R33/022 ,  G01R33/0283

Abstract: A target value of magnetic flux density and magnetic flux density actually obtained are made to coincide precisely with each other. An electromagnet control device comprises a current value determining unit for determining, based on a magnetic flux density instruction value, a value of current that is made to flow through a coil. The current value determining unit is constructed to execute a second process for determining, based on a second function, a value of the current, if the magnetic flux density is to be decreased from that in a first magnetization state, and a fourth process for expanding or reducing the second function by use of a first scaling ratio for transforming it to a fourth function, and determining, based on the fourth function obtained after above transformation, a value of the current, if the magnetic flux density is to be decreased from that in a third magnetization state.

公开(公告)号：US11346896B2

公开(公告)日：2022-05-31

申请号：US16927311

申请日：2020-07-13

Applicant: EBARA CORPORATION

Inventor： Haruka Takeuchi ,  Tomonori Ohashi ,  Ichiju Sato

IPC: G01R33/02 ,  G01R33/022 ,  G01R33/028

Abstract: A target value of magnetic flux density and magnetic flux density actually obtained are made to coincide precisely with each other. An electromagnet control device comprises a current value determining unit for determining, based on a magnetic flux density instruction value, a value of current that is made to flow through a coil. The current value determining unit is constructed to execute a second process for determining, based on a second function, a value of the current, if the magnetic flux density is to be decreased from that in a first magnetization state, and a fourth process for expanding or reducing the second function by use of a first scaling ratio for transforming it to a fourth function, and determining, based on the fourth function obtained after above transformation, a value of the current, if the magnetic flux density is to be decreased from that in a third magnetization state.