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:
Feb. 08, 1994
Filed:
Nov. 26, 1991
Ikuo Yamato, Hitachi, JP;
Norikazu Tokunaga, Hitachi, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A three-phase a.c. uninterruptible power supply includes a transformer providing isolation between an input and an output, a single-phase inverter, and a cycloconverter. The uninterruptible power supply operates to convert a d.c. voltage into a high-frequency a.c. voltage in the single-phase inverter, transmit the output voltage of the single-phase inverter in an isolated state, and convert the output of the transformer into a three-phase voltage having a lower frequency, such as 50 or 60 Hz, than the frequency of the output voltage of the single-phase inverter. This enables the transformer providing isolation to operate at a high frequency, thereby enabling the size of the transformer to be reduced.