Abstract: A transformer bobbin is described for holding one or more tapped windings so as to present a low profile. The bobbin includes a coil form which supports the windings and which carries at its ends an upper flange and a lower flange between which the windings are disposed. A plurality of spaced apart fingers are formed at least on the lower flange by slots which extend to the periphery of the lower flange. A terminal strip is carried by the lower flange beneath the fingers so that tap loops from a winding may each be passed through one of the slots and then to the terminal strip where each loop may be joined to an external lead.

Abstract: A shell-type voltage regulating transformer includes a magnetic core comprising a stack of modified EI laminations having a center leg forming two sections. One of the center leg sections defines a low reluctance magnetically saturable path while the other section defines a high reluctance non-saturating path. A primary winding is wound on the center leg for magnetically coupling with both sections and a pair of secondary windings are wound each for magnetically coupling with only one of the sections. The two secondary windings are connected in series opposing relationship to supply a substantially constant voltage to a load.