hall effect switch as encoder

[aruna1]

hi I was wondering can i use these hall effect sensors to make a wheel encoder.they are from ebay.
http://cgi.ebay.com/5pcs-NEW-A3144-A3144E-OH3144E-Hall-Effect-Sensor-J-/150503466115?pt=LH_DefaultDomain_0&hash=item230ab4a483

I want to know if i attach them in motors body can i use it to count rpm of the motor?
thank you

[aruna1]

no one?

[waltr]

It can be used but will require some addition support circuits such as amps. It will also require finding the correct placement on the motor to pick up the rotating magnetic field of the stator.
This is not a common method to measure the rotational speed of a motor. Probably due to the difficulty.

[aruna1]

It can be used but will require some addition support circuits such as amps. It will also require finding the correct placement on the motor to pick up the rotating magnetic field of the stator.
This is not a common method to measure the rotational speed of a motor. Probably due to the difficulty.

this is a hall effect switch so i guess i dont need amplification right?

[Soeren]

Hi,

Hall switches is used extensively in brushless motors - take a look at some of their datasheets to see how.
Take a close look at the datasheet of the (obsolete) Hall switch you are planning on using - and check its sensitivity in relation to the rotating magnet field of the motor.