Re: Power Supply-- more questions

Well now that the holidays are over.. time to get back to work. I've got my steppers planned out. I finally settled on a bit larger units than origianlly planned. 3.5v and 6.0A /phase parrellel producing 1160 oz-in.

Anyway I was wondering if someone could just double check my numbers on this power supply before I order the parts.
I can't quite get 25 times my stepper voltage as that would put me over the Gecko 80v rating. So I'm shooting for 78vDC to the drives. Therefore 78/1.4=56vAC 6.0A x 4 steppers =24A.

My Capacitor's should be C=(80,000*24)/78 C=24615uF I found some Cap's from DigiKey and here's the spec's
[page 977 in the Canadian Cataloge--if anyone feels like looking it up]

100v (working) 125v Surge.
18000uF
0.016ESR @120Hz -20Deg C [No idea what this is]
12.85 R.C. (A) @ 120Hz, 85Deg C [or this]

I have no idea if the above will work.. ok.. or if I'm totally off base. They want $41 CAD each. I would need two of them wired in Parrellel?? Also wondering about what make [material] the proper CAP should be made from.. as there seem's to be several choices? What got me looking at these ones was simply that they "looked" like one's I've seen in others project pictures.... The are Panisonic and are called "Computer Grade Capacitor's"

Next on the list is the Bridge Rectifier.. I don't think there is alot of science for these, I chose one, 35A @ 100V, 400A Max surge, 10.0 uA Max reverse current, 1.1V Max forward volt [peak] They want $4 CAD. [ Digikey also]

Is there anything else I missing? I seem to remember someone putting various other Resistors and what not in theirs.. ??

Thanks in Advance!
Jarrett Johnson


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