An ignition coil, which is also known as a spark coil is an induction coil in an automobile’s ignition system. It transforms a storage battery’s 12 volts to the thousands of volts needed to spark the spark plugs.
      This particular form of the autotransformer (an electrical transformer with only one winding and it has at three electrical connection points called taps), together with the contact breaker (a type of switch found in the distributor of the ignition systems of non diesel powered internal combustion engines) will convert the low voltage from the battery into the high voltage that is required by the spark plugs in an internal combustion engine. The purpose of the contact breaker is to interrupt the current flowing in the primary circuit of the ignition coil.
      Now days in modern ignition systems, there is no ignition distributor and ignition is electronically controlled instead and firing voltage is then achieved by one