PSN-L Email List Message

Subject: 4 pole neodymium magnet/s
From: "meredith lamb" mlamb1@..........
Date: Sun, 24 Dec 2000 10:20:16 -0800

Hi all,

Merry Christmas everyone.

Curiosity thought.  Anyone using 4 pole salvaged computer neo
magnets with regular coils in a seismo?  Somewhat akin to the

Even just using one magnet, with a coil moving laterally across
the face seems to be just as good as using a large old alnico
magnet with the coil between the poles in visual hand/meter

Two neo magnets mounted in the usual "U" iron frame fashion
seems to be 2 to 4 times output better, than using just one.  I
think their is 4 fields between the magnets....but they don't
seem to contradict the coil output at all.  Two minor fields
on each magnet, and the major attracting fields between the
spaced magnets.

I used old iron curtain rod brackets, mechanically coupled for
the "U" frame.  Each magnet is simply magnetically placed on
each inside face of the brackets.  This may lessen the overall
magnetic field overall.   I haven't tried any spaced but
magnetically attracting and facing magnets, without, a iron
frame but it could show a difference or change in result?

The coil works best when centered down and between the
magnets....unlike a usual alnico magnet where the coil is
roughly 1/2 in the magnet opposing faces.

I used a 2K "pancake" shaped coil.  I do note some eddy
current damping when the leads are shorted.  Naturally a
lower resistance coil would be better, or, 2-3 (2k) coils
in parallel would be more effective.

Think the subject has been covered before to some degree
in the past emails...but I dread spending days going through
all them past PSN emails files.....ha.

Take care, Meredith Lamb


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Larry Cochrane <cochrane@..............>