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:
Mar. 13, 2001
Filed:
Jul. 07, 1999
Abstract
A control apparatus for an electromagnetic actuator for driving a mechanical element by using an electromagnetic coil. The control apparatus includes a circulation circuit for circulating current to be supplied to the electromagnetic coil, a capacitor provided in the circulation circuit and to be charged by the current flowing through the circulation circuit, and a unit for, when the current supplied to the electromagnetic coil is stopped, forming a discharge path for discharging the capacitor and flowing current to an opposite direction through the electromagnetic coil. The current supplied to the electromagnetic coil is charged in the capacitor, then when the current having been supplied to the electromagnetic coil is stopped, the electric charge thus accumulated in the capacitor is discharged thereby to flow current to the opposite direction through the electromagnetic coil. Thus, the current caused by the induced electromotive force generated in the electromagnetic coil due to the stop of the supplied current can be canceled, so that the electromagnetic coil can be quickly demagnetized.