Power supply design

[Minesgeek]

Hello,

I'm a college student trying to get into cnc machining. So, to save cash for software I'm going to build my own power supply and drivers for the steppers. I have done a lot of research but there are a few things I need clarified. Here are the specs for the equipment I have or plan to use:

Taig Mill (cutting anything from plastic to steel)
3X Bipolar 276 oz-in steppers: Rated 4.5 volts, 2.8A/phase
3X L6208 Bipolar stepper IC: 8-52V input, 60V peak; 2.8A RMS output, 5.6A peak

At the moment those are my only design considerations. I believe the steppers are a little overkill for my mill, so I'm currently assuming that running at only 10x voltage and current limiting to ~1.5 Amps will work fine. Here are my questions:

Stepper motors are rated 2.8A/phase, could someone explain the /phase?
Should the power supply be regulated and what constant current should it be able to handle?

I'm primarily concerned with the /phase rating and the stepper requirements and how it effects power supply requirements. Any other suggestions would be much appreciated though!

Thanks!

[ViperTX]

With steppers you have to energize 2 phases at a time, a phase is basically a winding.

2 phases x 2.8 amps/phase x 3 steppers x 2/3 = minimum current rating of power supply (about 12 amps). It does not require regulation.

[pminmo]

Minesgeek,
You might find some help pn my power supply webpage: http://pminmo.com/simpleps.htm

[jlcortes]

power supply???

I have a power supply design for your aplication! It is a bit bigger than you expect hehehe.

It could be interesting for powerfull 48v DC servo aplications,

It is a two-transistors forward converter with 4000W (based on a inverter welder) it is based on common current mode switch-mode powersupply controlled called UC3845.

I started to draw a clear schematic but it is incomplete. I have a prototype working and i can get any information.
Jose Luis.

[Minesgeek]

ViperTX,
Thanks for the explanation, that was what I expected but I couldn't find a good description.

pminmo,
Thanks for the site, I have built a few power supplies using similar designs in my electronics courses. I'll check out the site a bit further.

jlcortes,
That design looks interesting, if you finish a schematic I would really like to check it out. I'll send you a pm with my email on it if don't mind sending the schematic to me.

Nick,

[ggg]

What about this?
Boost PC ATX Power Supplies to 24v..32v