Re: [CAD_CAM_EDM_DRO] First note-Help Mariss Help us with shielding???

Hi Tom,

> Electrical noise has been a real pain for me in many projects I have

worked

> on.
>

Thanks for all your advice so far. You didn't mention where you grounded the
encoder (signal level) cable. DC Brush motors are super dirty. For all the
robotics stuff I've done, I've always made the motor power supply completely
separate from the logic power supply. I would run the voltage regulator for
the electronics off a completely separate battery.

Has anyone placed a cap across the servo motor terminals? In all my work
with much smaller DC motors, I've always placed a cap across the terminals
at the motor to help soak up noise the motor wants to inject back into the
power supply. But, I've done PWM at 1KHz to control the speed of these
motors, not the 25KHz that the Gecko's use. I don't know if there would be a
problem with heating the cap or causing something bad to happen with the
amount of power involved here.

The fact that grounding the motor power cable helped, implies that some
nasty spikes are coming out of the motor and confusing everything around it,
not necessarily just the encoder logic. Just my interpretation of the runes.

From www.control.com
"Usually it is a contact opening an inductive load such as a motor. You can
purchase suppressors to put right across the motor. The suppressor is
usually a resistor/capacitor series combination. IEEE put out an electrical
noise guide book which discusses the many forms of noise and how to cope
with them.
"
Cheers,
Chris