Re: Power supply transformer setup questions...Capacitors

Dave,

The calculation represents the minimal acceptable capacitance for the
power supply where the ripple will be about 10% at full design load.
I'm building a 40VDC 10Amp power supply, and am using two 39000uF 50V
capacitors to lower the ripple even further. The capacitors are
relatively small 1.6" Dia X 3.5" long P10635-ND's from Digikey
costing about $14 USD each.

Extra capacitance in this application does not hurt, but after a
while ceases being cost-effective.

Tony

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<davemucha@j...> wrote:

>
> That brings up a unsettled question in my mind.
>
> What amperage is used for the capacitor sizing ?
> When one uses the equation of
> (C= (80,000 * I) / V)).
> C is the value in microfarads,
> I is the current
> and V is the voltage.
>
> If a motor is 5 volts, and 5 amps and one runs this at 25 volts and
> one amp, is the calculation on one amp and 25 volts ?
>
> If it is, I'm betting there are a LOT of WAY oversized power

supplies

> out there.
>
> if this is an empirical calculation based on actual data and using
> nameplate then that would be fine. But, it seems that IF it is

based

> on the watts calculation, then most of us probably have a way big
> power supply.
>
>
> Dave