In older automobile ignition systems, the high-voltage pulses are produced by means of breaker points controlled by a revolving distributor cam. When the points are in contact they complete an electrical circuit through the primary winding of the ignition coil. When the points are separated by the cam, the primary circuit is broken, which creates a high-voltage surge in the secondary windings of the induction coil. Breaker points have been largely replaced by electronic devices in newer...
