> >> >> When we did that we could hear virtuallu hundreds
> >> >> of relays clickking off held by residual magnetism.
> >
> >Well he "says" it was residual magnetism. I guess we have to
> >believe somehow he knows that's what it was, and not weak
> >springs or other mechanical problems.
> >
> Because the relay stopped hanging up when I reversed polarity.
You were there Rich? When did you work for the telephone
company in Europe?
> >That's right. With a weak enough spring, the relay won't have any
> >return force.
> >
> The relay did not hang up after I reversed the magnetic field.
You were there?
> >But if the iron is soft it should also have no flux storage.
> All types of iron can be magnetized.
Depends on how much you mean by magnetized. Certainly all iron
materials have ability to retain SOME amount of magnetism, but
with proper material selection and treatment it can be negligible in
applications like relays.
73, Tom W8JI
w8ji@contesting.com
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