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. 02, 1988
Filed:
Oct. 27, 1987
John M Ross, Annandale, VA (US);
George K Woodworth, Manassas, VA (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
An asynchronous multiphase switching method and apparatus are disclosed which transfers a system load between two asynchronous AC power sources in an improved manner. It operates as a make-before-break switch to provide uninterrupted power to the system load during the transfer while minimizing voltage and current fluctuations. The control circuitry allows energy to be supplied to the load during the transition without allowing current to flow between the power sources. A matrix of SCRs is used to transfer the load between the two power sources. The switches to be gated are determined by the relative timing relationships of the existing and takeover voltage waveforms. By altering the pattern of the switches which are gated and by controlling the direction of energy flow, the transition can be made between the power sources without interruption of power.