What's inside those $5 noise filters for cars that suppress alternator
and spark plug noise? I would like to homebrew the best and smallest
one practicable. See, e.g.:
http://www.7453217467431.com/product...1407 85227156

Ken KC2JDY

On Fri, 24 Feb 2006 12:32:56 -0500, Dot wrote:
Generally? A capacitor across the input side, a series inductor and a
capacitor across the output side. You're basic Pi filter.


What kind of 12amp choke can they put in there when the whole thing
costs $4?

More importantly, what ferrite toroid material and how many windings
should I use for my choke? It would appear that 4700 uF is often used
for the caps.

Ken KC2JDY