# Current through a voltage multiplier

Discussion in 'Electronic Basics' started by Roger Dewhurst, Jan 8, 2006.

1. ### Roger DewhurstGuest

How, if at all, does the capacitor size influence the current flow through a
voltage multiplier?

R

2. ### Pooh BearGuest

The 'Cockcroft' type ?

Bigger Cs will reduce their impedance but eventually it's D.C. load current that
determines the A.C. current. Larger Cs will 'regulate' better of course.

Graham

3. ### John PopelishGuest

Larger capacitors hold their peak voltage better till the next pulse
than smaller ones do at the same load current, so the charging current
changes from a low value long pulse (as a smaller cap charges back up
to peak voltage) to a higher value, shorter pulse (as the larger cap
charges back less voltage to its peak). In other words, the larger
the caps, the smaller part of the total voltage wave contributes to
the charging process, so the magnitude of the current has to be higher
during those shorter times, to transfer the same average current.
This applies to all capacitor input filters, not just those in
voltage multipliers.