On Tue, 27 Nov 2018 at 19:15, Art <ky1k@myfairpoint.net> wrote:

....

The silver colored wire, which I assume is the heating element is at the
center of the heating cable, it is spiral wrapped with some sort of very
small diameter multi stranded synthetic cord, with fibers so fine, I
can't see the individual fiber strands. Around the core is a layer of
what appears to be insulation. On the outside of that, the copper wire
is spiral wound around the insulation, at about 6 turns per inch. Over
that, is the outer sheath of the wire.

The outer wire cannot be copper as it would short the heating element. Odds
> are it is of higher resistance than the heating element and with
> temperature variable resistance, so that you get SOME resistance change
> with temperature.

You can measure the resistance of a section of core and outer "wires' to
see what actual resistances are - and of an end to end element section if
you have a "good" blanket.


Russell

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