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:
Jun. 20, 2000
Filed:
May. 29, 1998
Thomas J Bowers, New Berlin, WI (US);
Chuck F Der, Sykesville, MD (US);
James D Parker, Brookfield, WI (US);
Pillar Industries, Inc., Menomonee Falls, WI (US);
Abstract
An induction heating system having at least one power supply switching network is disclosed to provide selective power control to multiple zones of an induction heating coil to achieve a desired heat distribution in a workpiece. The power supply switching network includes a number of bidirectional switches, each connected in series with one another, and each connected in parallel with a portion, or zone, of an induction heating coil. The bidirectional switches are controlled by a computer that supplies a control signal having a duty cycle as determined by the computer and a multi-zone feedback circuit. By splitting the coils and inserting a switch in parallel with each coil, and each switch in series with one another, the coil is effectively split into multiple series connected coils, thereby being more effectively controllable while avoiding physical alterations to the heating coil. The present invention can therefore compensate for inconsistent characteristics in any particular coil by effectively regulating the power to each section, or zone, thereby regulating the heat applied to the workpiece.