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:
Sep. 14, 1993
Filed:
Nov. 15, 1991
Yasutsugu Kawaguchi, Tochigi, JP;
Makoto Ishii, Utsunomiya, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A power supply includes a rectifying section for rectifying a sinusoidal a.c. voltage, a switching section for receiving a voltage output from the rectifying section, and a smoothing section having a smoothing capacitor. The power supply is controlled to have a sinusoidal load current and includes a power source circuit having a first path for conducting current from the rectifying section to the smoothing section and a second path for conducting current from an inductor of the switching section to the smoothing section, circuits for sensing the current flowing through the first path and forming a reference current with a target waveform based on the sensed current, circuits for sensing the current flowing through the switching element and determining a conduction ratio of the switching element to match the waveform of the sensed current to the waveform of the reference current, and a control circuit for sequentially controlling a plurality of switching elements connected in parallel based on the determined conduction ratio.