around the core and against winding 28 secondary windings 48 and 50 lie between winding 28 and 32 and 32 and 36 respectively secondary winding 52 lies between primary winding 36 and magnetic cap 54 magnetic cores 56 and 58 lie within secondary windings 48 and 50 so that a complete interior magnetic core within the windings is achieved the magnetic circuit is completed around the sides of the coils by means of four fingers on each of the caps which are in direct contact and engagement for example finger 60 on cap 42 is in direct contact with finger 62 on cap 54 the inductive charge receptacle 40 is illustrated as having built in cooling there are coolant channels in cooling ring 64 and coolant channels in cooling ring 66 seen in both fig2 and 3 the coolant channels are connected to radiators the near side radiators 68 and 70 are seen in fig3 there are similar back side radiators coolant can flow from the channels into the radiators through normal convection or through phase change heat pipes as may be required by the installation the magnetic coupling is enhanced between the inductive charge coupler and the inductive charge receptacle by the thinness in the axial direction of the electrical windings in both the coupler and receptacle it has long been recognized that the ac resistance r ac of windings can be very much higher than the dc r dc resistance depending on the frequency winding geometry and the thickness of the layers an r ac r dc ratio up to 100 is quite possible winding resistance increases of this magnitude cannot be ignored when energy loss and heating of the coupler is important the original calculations were for.