Re: [CAD_CAM_EDM_DRO] Re: DRO - multiple items
Posted by
Bertho Boman
on 2000-04-07 17:25:40 UTC
Alan,
The complete procedure would be to first align the grating for largest signal swing (darkest position occurs when best aligned) and
then adjust the comparator threshold level for a symmetrical output duty cycle =50%. Repeat for the second channel and then adjust
for 90 degree phase.
Note, on a rotary encoder, twisting will affect the grating alignment and moving it straight in and out will change phase without
affecting alignment.
If you have only a digital output and no way to get in and look at the levels before the comparators, then twist for best duty cycle
and then adjust the phase.
Bertho
=======================================
beer@... wrote:
The complete procedure would be to first align the grating for largest signal swing (darkest position occurs when best aligned) and
then adjust the comparator threshold level for a symmetrical output duty cycle =50%. Repeat for the second channel and then adjust
for 90 degree phase.
Note, on a rotary encoder, twisting will affect the grating alignment and moving it straight in and out will change phase without
affecting alignment.
If you have only a digital output and no way to get in and look at the levels before the comparators, then twist for best duty cycle
and then adjust the phase.
Bertho
=======================================
beer@... wrote:
> Bertho Boman wrote:
>
> > For the quadrature decoders, each should be adjusted for best alignment (largest analog signal swing on a scope) and then the 90
> degree phase adjusted while watching that the "lines" alignment is not lost.
>
>
> I think that this alignment strategy would be most useful for analog
> output detectors. The more common detectors are digital output, and so
> alignment is best determined with a storage scope, checking for state
> changes 90 degrees out of phase channel to channel.
> ------ > snip
> Alan