[chbot] Odometry

[Michael Pearce]

An alternative to optics that is widely used in the 
automotive industry for speedo/odometer and RPM (Diesels 
and Fuel Injection) is to use a hall effect device with 
either a vane, or gear tooth.

A common arrangements are:

1. Gear Tooth/vane - Hall (Specific type) - Magnet

    > H =

2. Magnet - Iron Vane - Hall

  = | H

3. Magnetic Vane - Hall
  + H


All work well but do require careful alignment and gaps.
Depending on your hall type it may have logic output, or 
need a simple AMP and/or Comparitor setup to generate the 
pulses.


An Iron Vane setup is available from Soanar Plus for 
NZ$15.31+GST (ZD1900) Commonly used in Automotive ignition.

A hall effect sensor suitable for Notch sensor, gear tooth 
sensor, current monitoring etc is NZ$3.84+GST (ZD1902)


Mike

On Tuesday 31 October 2006 21:56, Carl Ranson wrote:
> I'd like to modify my base to correct for the slight
> differences in the motors and thought that odometry might
> be the way to do it.
>
> Anyone had experience with through hole type encoders
> (where the shaft goes through the encoder)?
>
> What about the home made reflective ones?
> Ta
>
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