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Old 01-01-2013, 03:51 PM   #25
knc1
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Device: Too many.
Sleep / Wake magnet assembly

When ordering my Kpw I had the choice of a $20 case without a sleep/wake magnet or a $40 case with the sleep/wake magnet.
Duh...

I admit it - I'm cheap - I got the $20 with the intent to add my own magnet.

After trying to make my own - I broke down an bought a magnet.

RadioShack part number: 64-1895 - a pack of two rare earth magnets for $2.19.

Each magnet is 3/16 (4.8mm) diameter and 1/16 inch thick.
Rather strong for their size: 10,000 gauss.
Much stronger and much smaller than the refrigerator magnet (which I had been using).

WARNING: Do not allow your credit cards (or any mag-strip card) to come close to this magnet!
That is: Don't put them in the case with your Kpw - you might just as well burn them.

The "natural" lines of force are from flat face to flat face.
This will wake the Kpw - but it would work much better if the lines of force where parallel to the case surface.

To do that, I made a "U" shaped, sheet steel, frame to bring the end face of the magnet that would be furthest away from the Kpw down to the surface.

The "legs" of the "U" are slightly longer than the thickness of the magnet.

There is a drop of "super glue" between the magnet and the steel frame. Just to keep the magnet from sliding out of place over time.
(Sliding it is the only way to get it off - 10,000 gauss is a lot of "pull").

With a US penny as a reference to the size of this device:

Pic: 1 - The rare earth magnet.
Pic: 2 - The steel frame.
Pic: 3 - The magnet inserted into (onto?) the frame. Note that the frame is about 2x the width of the magnet - This is a requirement.
Pic: 4 - A side view of the assembly. Note that the legs are slightly longer than the magnet is thick - This is a requirement.
Pic: 5 - Put it there.

Bring this assembly (open side towards Kpw) within 1/4 inch of the Kpw and it goes to sleep (from either "run" or from "off").

Final assembly will be to recess it into the foam liner of the zipper case with a touch of glue to hold things in-place.
Attached Thumbnails
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Last edited by knc1; 01-07-2013 at 01:12 PM.
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