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:
Oct. 05, 2021
Filed:
Jan. 31, 2020
Fuji Electric Co., Ltd., Kawasaki, JP;
Koji Murata, Suzuka, JP;
Jian Chen, Matsumoto, JP;
FUJI ELECTRIC CO., LTD., Kawasaki, JP;
Abstract
A switching period in a burst cycle includes three pulses, that is to say, a start pulse that turns on a low-side switching element, a main pulse that turns on a high-side switching element, and an end pulse that turns on the low-side switching element. A burst stop period corresponding to the magnitude of a load is set during a switching stop period. When the burst cycle approaches a cycle corresponding to a frequency close to the upper limit of the audible frequencies, a second off-threshold voltage of the main pulse is made equal to a first off-threshold voltage of the start pulse to narrow the on-width of the main pulse. By doing so, energy transmitted to the secondary side of a transformer is reduced and the burst cycle is shortened.