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:
Sep. 04, 1990
Filed:
Apr. 25, 1989
Takatomo Izume, Urawa, JP;
Kabushiki Kaisha Toshiba, Kawasaki, JP;
Abstract
A contol apparatus for a single-phase full-wave resistance welder in which anti-parallel connected thyristors are connected in series with a primary winding of a welding transformer and which controls a firing phase .theta.n of the thyristors to adjust a welding current, includes storage means for calculating and storing a square sum SK in such a manner that a sinusoidal value VK=K0sin.theta.K having a given peak value is divided at predetermined phase intervals (1.degree.) within a predetermined phase range (180.degree.), and the square sum SK=V1.sup.2 +V2.sup.2 +V3.sup.2 +. . . VK.sup.2 of the sinusoidal value VK with respect to each phase .theta.K is calculated in units of divided phases .theta.K (.theta.K=1.degree., 2.degree., 3.degree., . . . , 180.degree.) in advance, and Vx calculating means for reading out square sums Sn and Sm of the firing phase .theta.n and energization end phase .theta.m from the storage means and calculating a normalized effective value Vx of an effective voltage applied to the welding transformer.