Quoting chrysler1978@xxxxxxxxxxx:
> Simply said, current flow causes heat, end of story.
>
> Brad Hogg <----also a qualified electronics engineer.
> Winnipeg, Manitoba
Often, the story can be more complex that it appears. What DB is saying (and
it makes sense to me) is that a localized increase in resistance can be small
enough to not reduce the current by much (you need to remember, the current
depends on the TOTAL resistance of the WHOLE circuit, if the total resistance
is significant, a small local increase in the resistance will leave the current
flow largely unaffected). Then, if you focus on that small portion of the
circuit with increased resistance, it sees virtualy the same current as before,
and more heat generated due to higher R. If the wire is insulated, this heat
may have nowhere to go, so it will keep on heating it up. Let's push it a bit
further. This heat could increase R further, making things worse, till the
insulation goes, and the short occurs, and there is your increase in current!
Those simple discussions can be helpful to understand simple things like that,
which can help us diagnose problems. And the more "wrong" we happen to be, the
more we can benefit from them...
D^2
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