electrically connected based on this embodiment two other retaining devices 21 22 are also provided on a bottom end face 25 of the first partial coil 4 4 u2032 4 u2033 and a top end face 26 of the second partial coil 5 5 u2032 5 u2033 but are not electrically connected and these retaining devices 21 22 each form a second electrical terminal 9 9 u2032 9 u2033 10 10 u2032 10 u2033 to connect a coil subassembly 13 13 u2032 13 u2033 to a thyristor unit 6 6 u2032 6 u2033 as may be seen from fig2 4 a coil subassembly 13 13 u2032 13 u2033 sits on several electrically isolating support elements 27 which are disposed underneath the bottom retaining device 21 and the coil subassembly 13 13 u2032 13 u2033 and isolate or hold the bottom support plane 16 at a distance apart an electrically isolating support element 27 comprises an isolation body 36 and a preferably section type support body 37 disposed underneath in the embodiment illustrated in fig5 7 in which the partial coils 4 4 u2032 4 u2033 5 5 u2032 5 u2033 are disposed one inside the other the at least one retaining device 20 is disposed underneath the first partial coil 4 4 u2032 4 u2033 and the second partial coil 5 5 u2032 5 u2033 of a coil subassembly 13 13 u2032 13 u2033 and the bottom end faces 24 25 of the two partial coils 4 4 u2032 4 u2033 5 5 u2032 5 u2033 sit in a direct electrical contact with the at least one retaining device 20 this forms the.