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. 04, 2003
Filed:
Apr. 05, 2002
Applicant:
Inventors:
Mitsutomo Yoshinaga, Saitama-ken, JP;
Mizuki Utsuno, Saitama-ken, JP;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02M 3/335 ;
U.S. Cl.
CPC ...
H02M 3/335 ;
Abstract
A switching power supply has a bottom detection circuit ( ), which judges whether or not a bottom has been reached, based on a voltage of a capacitor (C ) that determines an off time of a switching element (Q ) that generates a voltage at the secondary side of a transformer ( ) and, in the case in which the judgment is made that a bottom has not occurred, a charging voltage for the capacitor (C ) is switched to a high-potential side.