At 09:22 AM 1/20/2002, Larry Alofs wrote:
>Someone ought to reverse-engineer one of these things to see what the VW
>solution really consists of.  The service bulletin says something about
>"active components" (transistors).

It's an active low-pass filter.  I don't know the time constants.  The
capacitor approximation was arrived at experimentally by people trying 10
uF and deciding that 20 worked better.  Dunno whether they did any math in
the process.  In general you want something that passes say five Hertz and
blocks say fifty.

david

--
David Beierl - Providence, RI
  http://pws.prserv.net/synergy/Vanagon/
'84 Westy "Dutiful Passage"
'85 GL "Poor Relation"