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:
Dec. 02, 1997
Filed:
Aug. 14, 1995
Randhir Singh Malik, Colchester, VT (US);
Ronnie Arno Wunderlich, Endicott, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A three phase input, boost power supply comprises first, second and third rectifiers for respective phases of the three phase input. First, second and third boost inductors are interposed between the first, second and third rectifiers, respectively and respective phases of said three phase input. A low pass filter is interposed between the boost inductors and the three phase input. A chopping switch is connected to an output of at least one of the rectifiers in parallel with a load to boost a voltage of the load. A current sensor is connected between the rectifier output and the load. The switch is activated in response to the current sensor sensing approximately zero current flow. The subsequent rate of current rise is proportional to the magnitude of the input voltage. The switch is deactivated based in part on a comparison of the load voltage to a reference voltage. Thus, the input current for each phase has nearly unity power factor, even when one phase drops out.