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:
Aug. 17, 1993
Filed:
Oct. 07, 1991
Abstract
In an apparatus for parallel operation of plural uninterruptable power source devices, each power source device includes at least one of an operation mode monitor for a logic operation on the output of the AC input monitoring circuit of each of the uninterruptable power source devices to feed the result thereof as a mode controlling signal to the mode controller, a parallel synchronizing signal generator for a logic operation on the output of an oscillating circuit which drives the invertor in each of the uninterruptable power source devices and, on detection of abnormality in the AC input, feeds the result thereof as a trigger pulse to the oscillating circuit, and a synchronization monitor for a logic operation on the output from the oscillating circuit in each of the uninterruptable power source devices and, when the differences between the phase of the output from the oscillating circuit of one of the triport uninterruptable power source devices and that from the oscillating circuits of remaining triport uninterruptable power source devices exceed the prescribed level, issuing a parallel operation release signal to open the switch of said one triport uninterruptable power source device that permits it to operate in parallel.