GB245069A - Improvements in or relating to transformers for use with electric welding machines - Google Patents

Abstract

245,069. Soc. Anon. des Ateliers de Secheron, (Assignees of W÷rtmann, F.). Dec. 23, 1924, [Convention date]. Regulating transformers.- In a transformer used for arc welding the no-load voltage is compulsorily increased as the transformer is adjusted for working with a lower welding current. In one form the primary winding is divided, the main part being on the limb A, Fig. 2, of the core and a subsidiary part on the limb B. The secondary winding is also distributed as shown. Tappings are provided on the primary; when the main part only of the winding is in use the no-load voltage is highest but the leakage is greatest and corresponds to low welding current. If a part of the primary on the limb B is cut in, the induction and no-load voltage decrease, but the leakage is less and a higher welding current is obtained. In another arrangement the secondary winding is divided and placed on different limbs of a core; tappings are provided on both parts so that as a portion of one secondary part is cut out more turns are added to the other part. In a third arrangement the secondary winding is distributed on the two limbs F, G, Fig. 4 of the core, that part of the winding on the limb G having tappings as shown. The variation in the no-load voltage may also be effected by adjusting the air gap between the main part of the core and the limb H. A combination of the means above described can also be used.