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:
May. 20, 2003
Filed:
Jan. 10, 2002
Warren E. Herwig, Oshkosh, WI (US);
Bryan Shupita, Mankato, MN (US);
Illinois Tool Works Inc., Glenview, IL (US);
Abstract
An apparatus to sense an SCR short circuit failure and prevent overheating of solid-state power supply equipment, such as a welder, during an occurrence of the short circuit failure is provided. The apparatus includes a detector circuit capable of sensing a short circuit of an SCR in the power supply equipment. The detector circuit senses each voltage of a poly-phase input and generates a fault signal upon substantially simultaneous detection of a zero-cross voltage condition for each phase of the poly-phase input. A control circuit is configured to receive the fault signal of the detector circuit and generate an output to prevent fault current flow through to power supply equipment.