NGK ignition coils play a vital role in providing a reliable ignition by allowing for the smooth and efficient operation of your vehicles engine. The fundamental principle is the same for all ignition coils. A voltage in the high kilovolt range up to 45,000 volts in modern vehicles must be generated from a low battery voltage of 12 volts. Therefore, the voltage is transformed and multiplied. This principle relates to traditional cylinder ignition coils and modern block ignition coils or pencil coils. The device contains two copper wire windings and a laminated iron core. The copper wires are insulated to prevent short circuits. The battery current fed through the primary winding produces a magnetic field whose strength is further increased by the iron core. When this circuit is opened, the magnetic field collapses, inducing a high voltage pulse in the secondary coil.