On 1/29/2017 1:48 PM, Gene Heskett wrote: > > Alan, ALL of the motor drivers are switchmode, with the current > regulation running at or above 20 KHz. And these noise spikes are > ringing at nominally 100 MHz. I have managed to get the xy motor noise > under control by takeing out the switchmode psu's, and putting in > tordoid transformers, bridge rectifiers, and the biggest electrolytic I > had in the drawers that had sufficient withstand voltage. Its a star > ground system, and the output cables to the motors are shielded, and the > shield grounded as it goes by this single bolt ground on its way out of > the box. The shielding extends both ways from that point but is not > connected either at the motor, or at the driver, just at the bolt. This > is std in such noisy machinery. >
I would also recommend bypassing those electrolytics with 0.01uf or so disk capacitors (or similar). Electrolytics have higher impedance at higher frequencies. Bypass capacitors help with high frequency spikes.