---------- Forwarded message ----------
Date: 20 JUL 1999 17:22:55.10
From: VAXGS::KATSAVOU@axpgs0.lngs.infn.it
To: ZACCHEO@axpgs0.lngs.infn.it, ORSINI@axpgs0.lngs.infn.it,
MARRELLIV@axpgs0.lngs.infn.it, CORTH@axpgs0.lngs.infn.it
Cc: KATSAVOU@axpgs0.lngs.infn.it
Subject: Ripple on TOHM CAMAC power supplies
Ciao a tutti,
Using the digital scope, we verified the ripple on the +46V capacitors.
It was ~ 1V p-p, (+40.5 -> +39.5), with a triangular-like shape with
period of 10msec (100Hz). The ``explanation'' is
- ``Equivalent'' load of ~ 10 Ohm (4Amps, on 40V -> 10Ohm).
- Time constant of 22mF * 10 Ohm = 220msec.
- Exponential drop after 10msec on 220msec time constant = 4.4%
- Given that the fully-rectified AC is ``recharging'' the cap at about
half time (msec), we expect ~ 2.2% drop * 40V ~= 1V
A presto,
Ioannis