Induction Coil

• A coil in an engine, often referred to as the spark coil, ignition coil or induction coil, is used for disruptive discharge. Disruptive discharge refers to the reduction of an insulator that can result in a spark, or electrostatic discharge, jumping through the insulator.
  
  

Ignition System

• The coil on an engine is contained in a vehicle's ignition system. The coil converts the 12 volts produced by the vehicle's battery into thousands of volts, which are needed to spark the spark plugs, which in turn ignite the air-fuel mixture.
  
  

Process

• Current from the vehicle battery is sent up the winding of the coil. The winding and capacitor then form a circuit. The stored energy in this circuit oscillates, producing a magnetic field in the coil's core. The core coil produces a much greater voltage than the outer winding, which is sent to the spark plugs in the form of 20,000 to 30,000 volts or more.