Herbert:

As far as the spark jumping the relay gap (if for some reason you cannot
gain access to a low voltage section of the circuit) you could use more than
one contact/relay: wiring the contacts in series will quickly reach a "safe"
distance...

Other thoughts;
  * is there an air intake (or exhaust) port that could be blocked? doing so
could do the job.
  * how about interrupting the mechanical coupling between the wheels and
the engine?
  * for really fast stopping of the engine you could cause the
piston/cylinder to try to act on something less compressible - such as water
by using a car windshield washer fluid pump with a small reservoir and hose
directed into the intake... though this might be too drastic.
  * you might want to reconsider changing the steering wheel direction as a
fail-safe - would be messy if it intermittently activated while moving at
speed in close quarters or near people... I'd lock the wheels as-is until a
valid steering signal is received...

Bruce.

>        I was thinking about something like that but it may be hard to find
a relay
> that can do it. The problem is that if the relay contacts aren't far
enough
> apart a spark will simply develop across the relay contacts AND the plug!
> :( The motor I am using (and no I can't change the kind of motor being
used!
> :) )uses a "coil flying by a magnet really quickly" approach to develop
the
> spark.
>
> Why I don't really like this idea either is that assuming I find a relay
> with contacts far enough apart it is still possible that on say a humid
day
> the spark WOULD jump across the contacts. I guess I could heavily modify a
> relay so the contacts are say 1cm apart, I believe that would be enough,
but
> being a safety device I'd rather go with something a little more "sure".
:)
> TTYL

--
http://www.piclist.com hint: To leave the PICList
mailto:piclist-unsubscribe-request@mitvma.mit.edu