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:
May. 11, 2021
Filed:
Oct. 30, 2018
Fuji Electric Co., Ltd., Kawasaki, JP;
Mean Well Enterprises Co., Ltd., New Taipei, TW;
Koji Sonobe, Matsumoto, JP;
Yu-Wei Chung, New Taipei, TW;
FUJI ELECTRIC CO., LTD., Kawasaki, JP;
MEAN WELL ENTERPRISES CO., LTD., New Taipei, TW;
Abstract
A switching power supply apparatus includes a switching device and a switching power supply control circuit for converting an AC source voltage to a DC voltage. A comparison circuit in the switching power supply control circuit produces an H-level output signal when its non-inverted input voltage exceeds a voltage value during each off-state period of the switching device. A delay circuit outputs a pulse signal after a predetermined delay time from detecting the H-level signal. This pulse signal indicates detection of a bottom point of drain voltage of the switching device. Since the output of the delay circuit is directly connected to the set input terminal S of a flip-flop, the switching device is surely turned on, without bottom skip, upon detection of the bottom point of its drain voltage.