Re: Audi's Cure for the Ignition wired/not wired radio

[Don Hoefer <hoefer@cary.eng.pko.dec.com>]

Phil asks;

>what i would like to see is a radio that worked the way the one in my 82 
porsche 924 worked.  this was before antennas in the windshield, but all 
you had to do was touch the key to the ignition (not even push it all the 
way in or turn it) and the power antenna would go up and the radio come 
on.  i've asked a couple of mechanics how this was done and they never 
could give a good explaination.<

A capacitive discharge switch would do it.  It activates when it
detects a small change in charge.  This happens when you touch it and
some electrons flow into you or from you into the switch, or when the
key shorts two charged and isolated metal polls somehow on or just
inside the ignition switch.  These are not so popular anymore because
they are static sensitive, they would trigger falsely and
unpredictably.  It would probably be pretty good inside an automobile
however.  The car body makes a good static shield and you would
contact the body before you contacted interior parts minimizing the
charge difference between you and the car and the cars interior parts.

Don Hoefer
'82 Coupe