The ignition coil does not change the direction of current flow hence it does not change polarity.  However, there are more coils in the secondary winding inside of the coil, thus there is more resistance to incoming current flow at the secondary winding terminal, so the coil’s high voltage output to the spark plugs will be less if the [...]

One of the people who looked this article over asked why I didn’t title it “Anatomy of an Aircraft Quality Terminal.”  I would probably have done that twenty years ago; now I’ll suggest that the term “aircraft quality” has no quantifiable meaning.  But that’s a topic for another article.  For now, take a few minutes [...]

The rule that makes 12-volts work so well is the one that says if you double the voltage, the amperage required to power that same accessory is reduced by half.  For example, the original 6-volt motor requiring ten amps of electrical current would only need five amps of electrical current to run at the same [...]

Condensers:  You can tell when a condenser has gone bad if your normally smooth running engine suddenly backfires and won’t rev up.  One way of checking this out is to remove the distributor cap, body and rotor.  Make sure the points are closed.  Turn on the ignition switch and place the high tension wire (from [...]