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:
Sep. 20, 2005
Filed:
Jun. 17, 2003
Applicant:
Hideki Hirosawa, Fujioka, JP;
Inventor:
Hideki Hirosawa, Fujioka, JP;
Assignee:
Kabushiki Kaisha Toshiba, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02M003/335 ;
U.S. Cl.
CPC ...
Abstract
A surge voltage detection circuit compares a stipulated voltage Vwith the drain voltage of a switching element, the drain voltage being applied by a smoothing capacitor. The comparison result is supplied to a switching control circuit. If the drain voltage of the switching element is higher than the stipulated voltage V, the switching control circuit inhibits the operation of the switching element. As a result, no switching operation is started, and the drain voltage of the switching element does not exceed the breakdown voltage of the element.