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:
Aug. 13, 2019
Filed:
Oct. 18, 2018
Fujitsu Limited, Kawasaki-shi, Kanagawa, JP;
Tatsuya Hirose, Yokohama, JP;
FUJITSU LIMITED, Kawasaki, JP;
Abstract
A switching power supply device includes a transformer including a primary winding and a secondary winding, a first transistor coupled to the primary winding, a first control circuit that outputs a first control voltage, a delay circuit that delays the first control voltage and supplies the delayed first control voltage to the first transistor, a second transistor that has a first terminal coupled to the secondary winding, a diode coupled to the secondary winding, a second control circuit that outputs a third control voltage used for controlling a switching operation of the second transistor, a control voltage generation circuit that generates the second control voltage, and a delay time control circuit that determines an ON period in which the diode is switched on and controls a delay time so that the delay time by which the delay circuit delays the first control voltage is shorter for a longer ON period.