Transformer having coaxial coils

Abstract

Transformer coils (19) are provided on a tubular section (5) of a coil former (3) at least one of the coils is separated from the next coil by mounting the second of said coils on an electrically insulating foil (41) wound around the first coil. Each of the two coils (19) is located in a winding space (27) which extends from the center of the tubular section (5) to both sides in the axial direction to boundaries (37) located at a predetermined distance from the ends thereof, whereas the foil (41) extends in the axial direction beyond those boundaries. In order to ensure an adequate insulation between the leads (17) of consecutive coils (19) and in order to enable subsequent thereto a simple check whether a coil (19) is indeed wholly contained within the prescribed winding space (27), the foil (41) extends in the axial direction substantially to the ends of the tubular section (5) and the foil is transparent and has visually observable marks (43) at the location of the boundaries (37) of the winding space (27).

Dependencies are inferred from the claim text.