Re: [CAD_CAM_EDM_DRO] Re: Sanity Check on Power Supply Capacitor Size

Thanks Dave, Aaron, Ron ... advice taken and will move forward slowly
and carefully.
As a novice ... the only way to go.

Luke

>Hi,
>
>The calculation is a little off.
>
>There is a 1 volt drop from the bridge, so the 18 becomes 17 before
>you use the 1.414.
>
>but, look at the wattage
>raw = 16.6 amps x 18 V = 299 watts
>then your DC voltage is 24.04 VDC
>299 watts / 24.04 volts = 12.409 amps at 24.04 volts.
>
>as you raise the voltage, you proportionally lower the amps.
>
>
>But for caps, the higher voltage means lower cap size, lower voltage
>means higher cap size.
>
>But, it appears you are using the power supply and not the total motor
>amps. That should make another difference.
>
>Also, the 'huge' caps are pretty cheap and physically small. you only
>need 25 volt rating caps.
>
>Even with the corrected numbers, the calc comes out to about 42,000µF
> but that is still not the proper number as it is not the total of the
>motors.
>
>Here is a fast pick, Digikey - P10007-ND $11.68
>56,000µF and 25 volts. The diameter is only 35mm, or 1.4 inches.
>pretty small actually.
>
>
>Dave
>
>
>