Re: [CAD_CAM_EDM_DRO] Newall sperosyn encoders

This was my first impression but LVDTs produce a varying voltage, dependent
on the position of the core. According to the documentation the output of
the spherosyn sensor is a pair of sine waves of varying phase. They also
mention that the sensor has six coils. I wonder what they are doing.
The phase comparator circuit must be pretty clever as well. It has to have a
resolution of better than 1/1000th of a degree.

Les

> > In a similar fashion, a long flat steel bar stock could have an edge cut
> > with a sinusoidal pattern. This could be "read" by a Hall-effect
> > sensor? Seems one has to induce a magnetic field in the "sine rack" (or
> > balls) in order to "read" them.
> >
> > Alan KM6VV
>
> Perhaps the Newall encoders use the balls as a variable core for coupling
> two coils as is done in an LVDT. It might be possible to cannibalize an
> LVDT to get the read head.
>
> Doug
>