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. 23, 1999
Filed:
Dec. 18, 1996
Applicant:
Inventor:
David L Lund, Minneapolis, MN (US);
Assignee:
GNB Technologies, Inc., Mendota Heights, MN (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H05B / ;
U.S. Cl.
CPC ...
219661 ;
Abstract
An induction heating generator is disclosed. The generator controls the power delivered to a work coil via a plurality of resistor/bias control switches coupled in parallel and a controller, thereby eliminating the expensive and difficult to troubleshoot SCR control circuits associated with prior art generators. By sequentially switching the bias control switches, the controller can progressively lower the input voltage to a controlled switch to thereby alter its conducting state to provide stepped power increases to the work coil. The work coil is de-energized by opening the bias control switches in reverse sequential order.