Re: [CAD_CAM_EDM_DRO] Hall Effect

I have had for many years a british hight gauge. It is a vertical tube
filled with one inch diameter ball bearings. A sliding head jams into the
space between the balls and a thimble interpolates with a 40 pitch thread.
I have always wondered whether the balls are slightly over an inch to allow
compression, but I have never taken it apart to measure them.

You could use smaller balls and inductive or capacitive pickups in
quadrature to measure the displacement, but the waveforms would be quite
unlike sine waves, requiring some massaging.

Ted Robbins

>From: "james owens" <wotisname@...>
>
>Hi,
>
>Being a novice at electronics maybe there is someone on the list that

could explaine why the following cannot be done.

>
>Take a 1/4" internal diameter tube of aluminum and mill a 3/16" slot down

it then fill itwith high grade ball-bearings. You have just made a very
accurate scale. If you then move a Hall-Effect device alone it lenth what
kind of signel do you get, is it analog or digital. If the former could the
signel then be feed into an analog/digital converter the rest is easy.

>
>Regards,
>
>Terry