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. 14, 1998
Filed:
Jan. 19, 1996
Markus Fritschi, Koelliken, CH;
Hans-Peter Meili, Seon, CH;
Allen-Bradley Company, Inc., Milwaukee, WI (US);
Abstract
The arrangement for the control of an electromagnet is intended for an electromagnet consisting of a Stationary core 7, a pickup coil 1 through which current flows temporarily after the switch is closed, a holding coil 2 through which current flows during the operating state, as well as a moveable armature 8 moving in relation to the core 7. Within a magnetically responsive switching circuit 5, which is connected in series with the pickup coil 1, a coupling sensor 22 is included, consisting of at least one winding which is linked to at least a part of the magnetic field of the electromagnet at least then when the air gap is open. At the instant when the air gap is closed, the voltage spike induced in the sensor coil 22 switches a controllable semiconductor 11, connected in series with the pickup coil 1 into a state of high resistivity via an electronic switching circuit arrangement. Thus, at the moment when the air gap is closed the pickup coil 1 is switched off without the use of any current The magnetically responsive switching circuit 5 utilizes the fact that at the moment when the air gap in an electromagnet is closed, a very steep rate of change in the magnetic flux density occurs. The switching circuit 5 is insensitive to extraneous magnetic fields.