|5764127||Inductive transmitters for conductor location|
Two vertical, parallel, horizontally spaced signal coils are connected in series but in opposite phase across an a.c. source. Thus a buried conductor located centrally beneath the coils experiences an alternating magnetic field whose strength is due to th...
|4837497||Variable transformer, reactor and method of their control|
A variable transformer, reactor having a core combining at least two complete core elements wiht a common yoke; primary winding divided into two independently fed sets of phase coils wound in opposite direction, arranged on symmetrical legs of core elemen...
|4500829||Advance and retard phase-shift transformer|
A phase-shift transformer circuit providing advance or retard phase shift at any predetermined phase shift angle. The phase shift angle is determined by the ratio of the main and short windings of the transformer primary. Two links are used to provide adv...