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. 10, 1997
Filed:
Dec. 08, 1994
Kenneth Opal, Oakmont, PA (US);
Harry Abrams, Pittsburgh, PA (US);
Peter Hammond, Greensburg, PA (US);
Halmar Robicon Group, New Kensington, PA (US);
Abstract
A power supply apparatus and method for supplying direct current power to low and medium voltage DC loads wherein a multi-phase transformer having multiple secondary windings provides multi-phase power to multiple power cells, each of which have a single DC output and are controllable by a modulation controller. The primary and secondary windings in the power transformer may be star- or mesh-connected; the secondary windings may be shifted in phase. Because the power cells can be connected in series, the maximum output voltage for each cell may be less than the maximum line-to-line voltage. The power cell output can have variable DC voltage and current which can be controlled using pulse-width modulation techniques. AC input power is converted to DC output power for each power output line. Output power modulation can be produced by interdigitating a selected number of carrier signals so that harmonic components reflected back to the input are attenuated.