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:
Jan. 25, 1983
Filed:
Jan. 02, 1981
Applicant:
Inventors:
Donald C McDonald, Worcester, MA (US);
Roger B Ela, Worcester, MA (US);
Dominic F Pignataro, Worcester, MA (US);
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01F / ;
U.S. Cl.
CPC ...
361145 ; 361149 ;
Abstract
In the electromagnet control apparatus described herein, demagnetization of the electromagnet and a workpiece held thereby, following a period of holding, is effected by stepwise adjustment of the phase setting of a power control means such as a triggerable, semi-conductor switching device, thereby controlling the average AC voltage applied to a full wave bridge through which the electromagnet is energized. Reversing switch means are interposed between the bridge and the electromagnet for reversing the direction of the energizing current at each successive step.