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. 14, 2006
Filed:
Jun. 02, 2004
Toshihiro Amei, Nei-gun, JP;
Toshihiro Amei, Nei-gun, JP;
SMK Corporation, Tokyo, JP;
Abstract
A self-excited switching power supply circuit is provided which reduces a discharge current generated when an oscillating field effect transistor () is turned on, whereby it is possible to reduce energy loss and generation of noise when switching is executed. A time constant of an ON-control circuit () is set such that when a polarity of a voltage of a feedback winding () has reversed, a gate voltage of the oscillating field effect transistor () exceeds a threshold voltage V. Accordingly, after a voltage of a primary winding () has become equal to or less than a power supply voltage, the oscillating field effect transistor () is turned on, and electrical charge stored in stray capacitance between the windings of the primary winding () and in parasitic capacitance of the oscillating field effect transistor () is discharged gradually.