Here is another formula:
Smoothing capacitor for 10% ripple, C = 5 × Io/ (Vs × f)
C = smoothing capacitance in farads (F)
Io = output current from the supply in amps (A)
Vs = supply voltage in volts (V), this is the peak value of the unsmoothed DC
f = frequency of the AC supply in hertz (Hz), 50Hz in the UK
For typical preamp +/-15V application, regulated from A/C 21V, 0.5A output.
C=5x1/(21x50) = 2380uF
For power amp +/- 32V application, supplies from A/C 32V, 2A output
C= 5x2/(45x50) = 6250uF
For both application, 10uF is overkilled already : |