Filters, and a ? for Mariss was Re: Rotor inertia.

Jon,

Not true.

The encoder input chain / channel is:

1) 1K pullup resistor to +5VDC, input to schmitt NAND gate (CD4093).
2) Output of NAND to 47K / 100pF low-pass (5uS RC delay).
3) Output of low-pass filter into 2nd schmitt NAND gate.
4) Output of 2nd NAND to quadrature decoder.

This filter will not pass any signal artifact narrower than 5uS and
squares-up slow rising/falling encoder edges. The low-pass bandwidth
matches the expected encoder roll-off frequency of 100kHz.

This filter has been tested with a 20' foot motor cable bundled with
unsheilded encoder cable in a common harness. The behavior and
accuracy of the servo was unaffected.

Please verify your guesses before presenting them as fact.:-)

Mariss

--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
>
> (snip)
>
> The encoder inputs on the Gecko 320 are NOT filtered, and in some
> systems that can be a problem.
>
> Jon