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

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Leslie Watts"
<leswatts@a...> wrote:

> Hello Abby
>
> A 1000VA should deliver 1000W into a resistive load.
>
> The sine wave thing comes into play with the secondary
> transformer AC voltage needed to get 50 VDC.
> That voltage will be 50 x .707 +1.5= 37 VAC.
>
> As for the capacitor... well that depends on what you will use the

supply

> for! For stepper or servo drives around 20,000 uF 75v would be

typical.

> With regenerative servo drives the capacitance might need to be

higher.

>
> Les
>
> Leslie M.Watts
> L M Watts Furniture
> Tiger Georgia
>
> Main page:
> http://www.lmwatts.com
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>
> -----Original Message-----
> From: Abby Katt [mailto:cnc@a...]
> Sent: Wednesday, September 01, 2004 5:07 AM
> To: CAD_CAM_EDM_DRO@yahoogroups.com
> Subject: [CAD_CAM_EDM_DRO] Power Supply Caps and Xformer
>
>
>
> Hello again my ever resourceful allies, :)
>
> So, I'm going to build a big power-supply, but I have 2 questions.
> First, the specs of the powersupply:
>
> Needs to be 50V @ 20A = 1000W
>
> Am I correct in assuming that I need a 2000VA transformer for this,
> as 2000VA would = 1000W (because of the whole sine wave thing), or
> would 1000VA = 1000W?
>
> Finally, what spec capacitor(s) will I need for this?
>
> Thanks!
> ~Abby
>
>
>
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