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. 09, 2006
Filed:
Dec. 25, 2002
Koichi Ueki, Tokyo, JP;
Kimitada Ishikawa, Saitama, JP;
Koichi Ueki, Tokyo, JP;
Kimitada Ishikawa, Saitama, JP;
Fuji Electric Co., Ltd., Kawasaki, JP;
Abstract
Conventionally, a non-conductive period is provided in a region in the vicinity of zero of an AC power voltage via a voltage detection circuitto turn off reliably. The FETmaintains the ON state within several switching cycles after the non-conductive interval to rapidly restore the magnetizing coil current, so that the magnetizing coil current rapidly increases. An object is to suppress beat noise in the electromagnetic device. Within a prescribed interval following the non-conductive interval, a partial voltage at a resistorof an output Vof a mono-stable circuitis added as a bias voltage to a detection voltage of a magnetizing coil current at a resistorand is detected by the ICThe ICdrives a FETwith a constant switching period after the non-conductive interval, thereby preventing the increase in the magnetizing coil current and resolving the problem.