Re: [CAD_CAM_EDM_DRO] Servo Dynamics 1525 servo drive noise

Shawncd wrote:

>Thanks to everyone that responded...
>
>Jon,
>To answer most of your questions here is what I have done so far. When I
>first got the machine home I installed a Advantech industrial computer with
>a Galil DMC 1040 control card. Next I installed Galils servo tuning software
>and Camsofts cnc software. As I tuned the servos for the new system I
>noticed that Z wasn't working, so I diagnosed and found the servo amp to be
>the culprit. After searching all over tarnation for the best price on a new
>/ used one. I found one that was identical, except for it has the latest
>revisions. (electrically the board looks a little different from the
>original) After installing it I noticed that with just axis Z plugged in
>there was silence. No whining noise, as with the other drives. So that's
>when I started questioning the older drives. Maybe the older units just
>sound this way because of the lower frequency. And the newer revised
>versions have the fix for this nusense noise. Or maybe the other two are
>about to fry as well. Which would make sense because there all the same age.
>Anyway, the other two older drives seem to function and hold tolerance. But
>it started to make me wonder if I should start looking for two more drives
>to replace the others. With hardly any support coming from Servo Dynamics
>this was my next best place for info.
>
>

Well, this kind of noise can wreck your hearing, if you don't lose your cool
and samsh the thing first. Apparently the old SD amps used bipolar
transistors,
the one I have part of the manual for used newer FETs at 16 KHz. I run my
servo amps at 100 KHz, so I definitely don't worry about hearing that.
Yes, if you can find some newer amps, you ought to replace them. I doubt
it has anything to do with them going bad. Running them at 5 KHz, it
wouldn't
take much magnetic coupling to make a loud whine.

Jon