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:
Nov. 17, 1981
Filed:
Dec. 19, 1979
Frederick A Stich, Milwaukee, WI (US);
Siemens-Allis, Inc., Atlanta, GA (US);
Abstract
A tap changer voltage regulator permits a tap changer switch selector contact to engage an open-circuited new tap without arcing and has a half-tap voltage auxiliary winding which permits halving the inter-tap voltage and doubling the number of steps, and also has an auxiliary switch system. An auxiliary static switch circuit initially connects a first tap selector in series with a circulating current limiting resistor and a load to prevent load circuit interruption. An auxiliary selector switch initially coupled to a second tap selector and is in series with a normally-closed switch through which the load current and circulative current flow. The normally-closed switch is shunted by a second static switch circuit. The first static switch is not gated until the first tap selector has attained its new position, precluding initial arcing. The normally-closed switch is then opened; subsequently gating current is removed from the second static switch so that load and circulating current are statically interrupted at current zero. The selector may then be arclessly disconnected from the second tap selector and moved to contact the first tap selector.