Re: [CAD_CAM_EDM_DRO] Hybrid Connectors Was Re: availability of composite multiconductor cable?

mrgamber wrote:

>This is a servo system. I will have 1000uF caps on the motor power
>inputs on the gecko 320's.
>

That has nothing to do with filtering the PWM OUTPUT of the drive.

> What is meant by commodity motor drive?
>
>

Low cost units, which may have cut corners to keep the cost down.

>Do Gecko 320's output PWM?
>
>
>

Yes. And, since there is no output filter, the motor output wires carry
voltage pulses of zero to whatever your DC supply voltage is, with
voltage rise times of 100 nS or less. that is a dV/dT of about
7x10^8 V/uS! That is a SERIOUS source of electrical interference.
I designed my own servo amps, and used an output filter which reduced
the magnitude of these high frequency radiations by a factor of roughly
100. I have had no problem with interference (I can ever use a radio
right on top of the CNC control) and I didn't even use shielded cable
for the motor output. All models of Gecko drives use a form of PWM
without output filters to drive the motors, stepper or servo. I suspect
Rutex does the same.

Jon