capacitance calculation along dc source

enjunear said:

The voltage on the capacitor will be equal to the voltage of the power supply, so it should have a rated voltage of at least 20kV. In practice, you typically oversize the cap's voltage rating, depending on the type of capacitor used and potential voltage transients that can occur. In most of my systems, we operate with 28Vdc, so I go with 50V or 100V parts. I'm not sure how that translates to the kV range... you may just derate by some percentage?

Click to expand...

zeeshan728 said:

thanks for your reply,,
it means the voltage rating of capacitor will be roughly double of input voltage...but what will be the capacitance rating is it will in nanoFarad or picoFarad..how to calculate that... ??? as the frequency in this case will be zero....

Click to expand...

enjunear said:

The capacitance should be determined by what the cap is supposed to do. If this is being used for bulk energy storage, then the value will typically be big.... mF or Farads. For filtering of smaller transient signals, the values will more commonly be in the nF and uF range. This is highly dependant on the load and desired output ripple performance.

Click to expand...