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:
Jun. 13, 2000
Filed:
Mar. 17, 1998
Minoru Maehara, Matsubara, JP;
Masanori Mishima, Hirakata, JP;
Naoki Onishi, Kobe, JP;
Yoshinobu Murakami, Hirakata, JP;
Matsushita Electric Works, Ltd., Osaka, JP;
Abstract
A power source device is so constituted that a first capacitor connected across DC output terminals of a rectifier is made to be of a relatively small capacity, a resonance circuit is formed by a primary winding of a transformer and a second capacitor, first and second switching elements connected in parallel to a smoothing capacitor are alternately made ON and OFF to cause currents to flow, a both-end voltage of the first capacitor drops to be substantially close to zero volt even in a period in which a source voltage of an AC power source becomes substantially zero, and an input current can be drawn in smoothly over the entire range of a cycle of the source voltage of the AC power source, whereby higher harmonics of the input current can be reduced, a pulsation of the current flowing to a load can be minimized, and required number of parts for the power source device is reduced to be able to realize circuit simplification and cost reduction.