by Tom Carnegie
All analogies are flawed. If they were perfect, they would be
the thing they were trying to represent. Analogies do serve a
purpose though. They can be a handy teaching device if you
don't get too carried away. Representing electricity with a
hydraulic analogy has been done for years and with some
success. As I mentioned before, of course there are flaws,
but some things translate well. In this analogy, the coil will
be a bucket. A bucket that holds electrons.
In a normal ignition system, the bucket is filled at leisure,
and at the correct moment, something triggers it to dump (the
points of a distributor, for instance).
In a T system, the bucket dumps when it is filled to a certain
level. The need is anticipated and the filling operation
begins in the hope that it will complete at the correct
moment. It supposes that if all four coil's sensing devices are
set to dump at the same level, then it will take the same
amount of time to fill them. This is roughly true.
Unfortunately, for the Montana 500, we don't want anything
to be rough. The main reason that the coils dump at different
times, assuming that they are adjusted the same, is coil
vagaries. In actual fact, as "electron buckets" all coils leak.
It stands to reason that if coils leak they probably leak at
different rates. Also the buckets may be shaped differently
(different wire size, or more turns of wire, for instance).
Some buckets may have wide tops that are easy to fill. Some
may have narrow tops that make filling more difficult. The
question then becomes, "how to minimize the variations?"
(end of article)