capacitor size for cnc machine

[tacromx]

hi friends , can anyone tell me what is the best value capacitors for 36v 12A power suppl i am building

thanks in advance

 

[IanP]

You will regret if you use less than 1000µF per 1A, what gives you at least 12,000µF capacitance. The nearest value is 15,000µF (rated for 50Vdc) and this should be roughly your choice..

 

[Kral]

The value depends somewhat on the type of supply, but here's a rule of thumb that I've found useful for a simple full wave rectifier with a capacitor input filter:
C = 10/(2*Pi*f*R)
will yield 10% ripple and 10% regulation (no load to full load). The values scale roughly linearly over a range of about 4:1.

Units:
C Farads
f Hertz
R Ohms

This rule gives a good starting point. In your case, the result is 8800 µF. Double the capacitance yields half the ripple, half the regulation %.

I hope this helps.