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:
Nov. 09, 2004
Filed:
Feb. 19, 2003
Katsumi Kobori, Miyagi, JP;
Masami Okada, Miyagi, JP;
Sony Corporation, , JP;
Abstract
The present invention provides a switching power supply which includes a main rectifying and smoothing circuit ( ) and a secondary rectifying and smoothing circuit ( ) for rectifying and smoothing an output obtained at a secondary coil ( ) of a converter transformer ( ) whose primary coil ( ) is supplied with a switching output from a switching element ( ) which switches a direct input. A error detecting circuit ( ), which is driven by a secondary rectified and smoothed output from the secondary rectifying and smoothing circuit ( ), detects a main rectified and smoothed output from the main rectifying and smoothing circuit ( ) to be supplied to loads so as to control the switching operation of the switching element ( ) by the PWM controlling circuit ( ) so that the main rectified and smoothed output is caused to be a predetermined state, and compares the voltage of the secondary rectified and smoothed output with the voltage of the main rectified and smoothed output so as to change the operation state of the PWM controlling circuit ( ) to the standby mode in case the voltage of the secondary rectified and smoothed output declines to come below the voltage of the main rectified and smoothed output by a predetermined value.