-----Original Message-----
From: Bill L. Fuqua <wlfuqu00@uky.edu>
To: ko4nrbs@yahoo.com <ko4nrbs@yahoo.com>
Cc: amps@contesting.com <amps@contesting.com>
To: <amps@contesting.com>
Date: 05 September 2002 04:56
Subject: Re: [Amps] Computer Grade Electrolytic Capacitors vs. Radial
>For an inductive input filter the RMS ripple current is equal to the output
current if you have a >single phase supply. For a capacitive input filter
the max ripple current will be equal to the >square root of 2 (1.414) times
the DC output current.
Doesn't it vary with source resistance and C/R values? I use a rule of thumb
of 3x for capacitive input - it was very instructive putting a .1 ohm
resistor in the bottom of the capacitor stack and hanging a 'scope across
it. The example circuit in the Duncan software has a cap input PSU putting
450V across 5k. DC current is 89mA, rms current in the cap is 226mA and
248mA in the transformer winding.
Steve
|