Re: CNC power supply question

What makes one supply better than another is a tough question. A
standard unregulated power supply is made up of only a few
components. Transformer, rectifier, and a cap everything else is a
bonus. There are very simple and that's where their strengths are,
as they are very robust and very reliable. A good unregulated PS can
usually give up to 3 times rated amps for a second or two without
damage, they can do this about once a minute every minute for their
entire life. Another type of power supply will more than likely have
problems with this and wouldn't make it through the first few over-
current draws without cooking. That's the beauty of simple.

Home-made VS Commercial

There is very little difference between the designs of one
unregulated PS to another; all the basic parts are there. The ones I
sell I have custom made for servo or other hi-draw applications.
Jerry's or Doug's PS have all the same parts as everyone else's they
just market (as do I) to the hobbyist. Big industrial suppliers will
seldom talk to a hobbyist for any length of time, we on the other
hand (I'm guessing on the other two) will talk to you.

What ever you decide, make sure you talk to your supplier and they
will guarantee their product in your application and they offer a
warranty (we offer 1 year), if not find another supplier.

Lastly, a good PS is not cheap. Unregulated power supplies simply
require mass, my 65VDC @ 20 Amp supply comes in at a scale tipping 35
pounds. That mass (weight) costs money, but that same mass is what
gives it the properties that let it handle the high draw applications.

If you would like to chat over design issues please feel free to give
me a call at 207-637-2523 anytime before 10 pm EST. It's a work
phone so don't feel weird about it.

I won't try to sell anything :)

Aaron Moss
www.IndustrialHobbies.com




--- In CAD_CAM_EDM_DRO@yahoogroups.com, "snagglexr650"
<snaggletto@c...> wrote:

> Hello,
>
> I'm trying to get the 'big picture' on designing my own servo
> based cnc control using a Gecko based system. I'm currently trying
> to tackle the power supply issue; Why some kinds are better than
> others and how to determine PS size from the motor specs in

general.

>
> I've read here and elsewhere that the varying loads associated
> with CNC motor control is a problem for commonly available
> regulated/switched power supplies.
>
> What makes a 'homemade', unregulated(?), PS (Jerry's PS, or Doug
> Fortunes 1kw/1.5kw monsters) better at handling varying loads than
> the 'comercial/professional' grade regulated PS you see on Ebay or
> other retailers?