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:
Jun. 17, 2003
Filed:
Mar. 13, 2002
Applicant:
Inventor:
Eiji Takegami, Nagaoka, JP;
Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H02M 3/24 ; H02M 3/335 ; H02J 1/00 ;
U.S. Cl.
CPC ...
H02M 3/24 ; H02M 3/335 ; H02J 1/00 ;
Abstract
A switching power supply for preventing the inflow of an electric current from an external when it stops operating. A transistor is connected between a gate of a MOSFET and a first terminal of a secondary winding where a positive voltage is induced when a switching element turns on. A Zener diode is connected to a base of the transistor When the switching element is in an on state, the Zener diode turns on the transistor by a voltage Vson generated in the first terminal of the secondary winding thereby supplying the voltage Vson to the gate of the MOSFET