Hi,

Has any body used a HALL EFFECT direction and speed sensor? I am trying to use Allegro - A3422EKA sensor and am confused about choosing the right magnet for the application.

I can use either a ring magnet or a magnetic strip rolled in a circle to form a ring magnet.

The requirement is that the pole width should be 3mm. i dont know whether i can find a 3mm pole width multipole ring magnet...

if some body has used any such hall effect direction and speed sensor please let me know...

 

My guess is that the ring magnet required has prepositioned pole pairs, so that a 1 in ring would have 13 pole pairs. making one might be difficult What would be the result if a ring with faces N-S were cut or broken in half, halves fliped ang glued, might give two counts per revolution, with direction.

 

Thanks a lot Bernard.

I contacted few magnet manufacturers yesterday. i came to know that such multipole magnets can be manufactured by using technique called anisotropic injection of energy into magnetic material.

dont know the cost of such ring magnets, but magnetic strip are being sold pretty cheap...about 20 usd for 30 meter strip with multipole configuration....

thnks