Is there an online calculator anywhere ? or failing that what sort of "packing factor" for 0.08mm (+/- .005mm ) winding on a relay coil. I have a good idea of the weight , subtracting an estimate of the plastic former and this would give the length from the density of copper but number ot turns ?. Impregnated coil so cannot count-off turns Rectangular section to coil , on the inside anyway, 14x 16.4mm , 16.8mm width, outer layer is curved at "corners" and bulging (from the winding not abuse) so more scatterwound than precise regular lay-up . Outer dimensions of 21.4mm bulge / 20.3mm , or so, at outer edges one way and 23.4/22.2mm , the other, a bit of geometry would give a good idea of the volume of this space but what ratio of that volume would be copper and what air+varnish, then what sort of weight would be contributed by the varnish?

- posted
11 years ago