RE: [CAD_CAM_EDM_DRO] Re: Power Supply Caps and Xformer

Abby,
Computer grade electrolytics are typical. They are widely
avalable new or surplus, but very old ones can get leaky
and should be avoided. I have built many supplies from
10 year old or so new old stock with no problems though.

Sounds like you may be using a regenerative drive, so
decel can pump up the supply to higher than nominal. That
braking energy is stored in the supply cap, so a higher
value might be in order...I use 40,000 in my 80v 3kVA supply.
That limits regenerative pump up to about 5v.

For servo amp voltage requirements I do the following:

Take max amp rated voltage...

Subtract 10% for line voltage variation

Subtract calculated regen voltage rise ( this is calculated
from machine specifics and capacitor supplies.

Much more information on this at
www.galil.com

Les

Leslie M.Watts
L M Watts Furniture
Tiger Georgia

Main page:
http://www.lmwatts.com
Engineering:
http://www.lmwatts.com/shop.html
Cnc surplus for sale:
http://www.lmwatts.com/forsale.html
Carved signs:
http://www.lmwatts.com/signwp.html

-----Original Message-----
From: Abby Katt [mailto:cnc@...]
Sent: Wednesday, September 01, 2004 9:20 AM
To: CAD_CAM_EDM_DRO@yahoogroups.com
Subject: [CAD_CAM_EDM_DRO] Re: Power Supply Caps and Xformer



Les, Hi

This is going to be for Servo drives, like the nice big (the biggest
ones) motors Dan Mauch has on his website.

I knew about the voltage formula, so that one is easy. But thanks. :)

What type of capacitors are best?
Cheers,
~Abby