[sdiy] Small magnets

[Ian Fritz]

At 12:54 PM 12/11/2003, Scott Gravenhorst wrote:
>As a kid, I remember my dad bringing home a roll of plastic magnet material
>that was easy to cut into strips or whatever with metal shears (actually, I
>think heavy duty scissors was sufficient).  This is the same stuff that
>flexible refrigerator magnets are made of.  It was, perhaps 3/32 of an inch
>thick, but I've seen it as thin as 1/16.  What I don't know is if this
>material is magnetically strong enough to work with keyboards made from reed
>switches.  I can only guess that if refrigerator magnets are made from it
>that it might be fairly inexpensive and widely available.  Does anyone know?
>  I suppose an easy test is to just cut a refrigerator magnet into pieces and
>try it.


Scott --

I use small pieces of refrigerator magnets with Hall-effect ICs (linear and 
switching).  The main problem with them is that they are not uniformly 
magnetized, so for example if you cut a small piece, half of it may be 
magnetized in one direction and half in the other!  On the other hand, you 
can whittle them to size to get the sensor response how you want it.

   Ian