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. 25, 1985
Filed:
Nov. 03, 1982
Jirou Kino, Seto, JP;
Toshirou Uemura, Nagoya, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A switching power source device, in which a DC voltage obtained by rectifying an AC voltage is converted by switching elements into an AC voltage, which is subjected to voltage conversion by a transformer and rectified by a rectifier circuit to output a DC voltage therefrom. In one embodiment, a resonance capacitor and a saturable transformer form a series resonant circuit, and switching elements are subjected to frequency modulation control. In another embodiment, an inductor connected in parallel with a non-saturable transformer, and a capacitor connected in series to the same transformer, form a series resonant circuit, and the switching elements are subjected to frequency modulation control. In each embodiment, the series resonant circuit is subjected to frequency modulation control, and the electric currents from the switching elements do not rise and fall suddenly. Accordingly, switching losses and noise can be minimized, and the output voltages can be controlled easily.