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Encapsulated Mercury Switch for Welte-Mignon
By Bob Hodge

[ Herb Lindahl wrote in 100422 MMDigest:

> I would like advice as to a more modern, safer switch that I could
> install in its place.

I offer this with some trepidation, but so far have no reason to doubt
its' worth.  I acquired a heavy duty, glass encapsulated mercury switch
and wired it into the circuit for the cup and finger of the original
Welte switch.  I found a suitable position on the linkage which would
allow a full make or break of the mercury pool and affixed the capsule
to it with a small cable tie or two.

The switch probably has some type of identification number and I remember
it was made by General Electric, probably sometime in the 1920s.  It
uses a pair of heavy but still very flexible leads, insulated with
small porcelain beads, and it doesn't heat up in the least even after
hours or more of use.  And over a couple of years time.

If there is interest, I can probably find a number on the glass -- but
again, this switch is a real antique.  A better solution might be to
use a smaller switch to control a 110-volt relay with suitable
contacts.  I just happened to have this switch on hand.

Best!
Bob Hodge


(Message sent Mon 26 Apr 2010, 18:47:21 GMT, from time zone GMT-0400.)

Key Words in Subject:  Encapsulated, Mercury, Switch, Welte-Mignon
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