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:
Oct. 18, 2005
Filed:
May. 08, 2003
Shin Nakagawa, Tokyo, JP;
Shin Nakagawa, Tokyo, JP;
Fidelix Y.K., Tokyo, JP;
Abstract
A switching power supply apparatus which has an input power source; a transformer having a primary winding, a secondary winding, an input winding and a magnetic flux canceling winding being connected to the secondary winding in series; a main switch for switching an electric current going through the primary winding; a bypassing capacitor for bypassing the primary winding; a sub switch for clamping a surge voltage, which is generated in the primary winding; a clamping circuit constituted of the sub switch and a clamping capacitor; a first rectifying switch for rectifying an electric current going through the secondary winding and the magnetic flux canceling winding during when the main switch is being OFF; a second rectifying switch for rectifying an electric current going through the magnetic flux canceling winding during when the main switch is being ON; and a smoothing capacitor for smoothing an electric current going through the magnetic flux canceling winding; and the magnetic flux canceling winding is provided in a direction that is opposite to a direction of a magnetic flux generated by the input winding, the primary winding and the secondary winding; and wherein an intermediate tap is provided in the primary winding so as to supply an electric current coming from the input power source to the main switch via the input winding and the intermediate tap.