NGV Ignition Coil

The ignition coil (also called a spark coil) is an induction coil in an automobile's ignition system which transforms the battery's 24 volts to the thousands of volts (20 to 30 thousand volts or more) needed to spark the spark plugs. It has an internal resistor to reduce the voltage and some rely on a resistor wire or an external resistor to reduce the voltage from the cars 12 volt wiring flowing into the coil. The wire which goes from the ignition coil to the distributor and the wires which go from the distributor to each of the spark plugs are called spark plug wires or high tension leads.

This specific form of the autotransformer, together with the contact breaker and a capacitor, converts low voltage from a battery into the high voltage required by spark plugs in an internal combustion engine.