Re: My power supply calculations - Light Comes On

Actually, while sitting on The John* I finally clued into what Dave
had mentioned about going by power instead of amps.

If I had 5 volt 3 amp steppers thats only 15 watts. When I increase
the voltage to 30, I still have to keep the actual power the same or
I have glowing/molton motors - so thats only 1/2 amp at 30 volts,
not 3 amps at 30. Total power supply required for 4 axis would only
be 2 amps, not 12...

I've also been searching for Nema23 motors and noticing that most
are below 5V. Paul Jones (CNC on a Budget) has 200oz/in Nema 23s
that are 1.7v 3.4 amp. If I sized the supply for those I could drop
the voltage to 20ish and still have them zooming along nicely.

1.7V x 3.4A = 5.78 watts
5.78 watts/20 volts = ~0.3A

A 2 amp 14VAC transformer would be plenty for those motors. If I
went for 4 amp, that'd be more than enough for any motors I'd likely
be using for PCB milling.

Now the cap can be 80,000 * 5 / 20 = 16,000 uF - Closest being
18,000uF @ 25v but I'd go 35 cause I'm paranoid :D

Of course I still have to see what size transformers and caps I can
get around here for the exact ratings. But I'm still down to the $40
CDN range instead of over $100.

* "The John" is a patented human intelligence boosting device. All
rights reserved etc.