| 摘要 |
1293134 Supply systems for resistance welding apparatus HADDON TRANSFORMERS Ltd 21 Nov 1969 [28 Nov 1968] 56492/68 Heading H2H [Also in Division H1] In resistance welding apparatus comprising a transformer having a laminated core and primary and secondary windings, the primary winding being connected to an A.C. mains supply via switching apparatus which is controlled by a timer, the transformer core has an air-gap 16 in one of its limbs to reduce unidirectional flux therein. It is stated that this flux may result from unbalance of a pair of switches (ignitrons or thyristors) in the primary circuit or from the action of the timer; the welding electrodes are connected to the secondary winding. The core may be an overlap type core with groups 1-15 of laminations, each group comprising a plurality of butt-jointed laminations and an outer lamination having an overlapped joint. |
