Small magnets needed for position sensing
Small magnets needed for position sensing
(OP)
I'm looking for small magnets that can be mounted on a turnscrew or rotating shaft. They are going to be used by a Hall sensor to detect position. I'm looking for magnets that could be as small as 1/18". Any ideas where I can find something like this?





RE: Small magnets needed for position sensing
RE: Small magnets needed for position sensing
You could simply snip off a small piece. Or, you could wrap the whole assembly with a piece and get more information about the exact position.
Or you could go another route and use a rotary encoder, e.g., potentiometer or resolver, and get tons of position information with high accuracy and precision.
TTFN
RE: Small magnets needed for position sensing
RE: Small magnets needed for position sensing
1.Having a needle/straightpin/turnscrew assembly in contact with a PM at the base mount. Some of the magnetic lines will appear at the tip.
2. Magnetize the turnscrew or turnscrew nut permanetly
Try to eliminate "problems" before trying to solve them.
RE: Small magnets needed for position sensing
RE: Small magnets needed for position sensing
aspearin1
RE: Small magnets needed for position sensing
http://www.thomasregister.com
and type Magnets under Product or Service, which will return 222 companies to approach to with your magnet specifications
RE: Small magnets needed for position sensing
SmCo are very brittle, they crack and chip very easily
NdFeB corrode so they need coating after any machining
We have used both types for Hall probe sensors on brushless motors, they do give plenty of flux. The size used is 3.0mm thick and about 4mm square, mounted in a non-magnetic (titanium) retainer. I think the airgap between the magnets and the hall sensors is about 1-2mm.
RE: Small magnets needed for position sensing
http://www.stanfordmagnets.com/magnet.html
http://www.rare-earth-magnets.com/
http://www.dansdata.com/magnets2.htm
http://www.shinetsu-rare-earth-magnet.jp/e/rem.shtml
etc. for more info