Coil Ignition System It is also known as a battery ignition system. As shown in fig. battery ignition system a four-cylinder engine consists of the following essential components : (a) Battery (b) Ammeter (c) Ignition switch (d) Induction coil (e) Contact breaker (f) Condenser (g) Distributor (h) Spark plug Coil Ignition System Diagram The battery ignition system is divided into two circuits i.e. primary and secondary circuits. The primary course starts at the battery and passes through the ammeter, ignition switch, primary winding, and contact breaker points to the ground. One end of the condenser is connected to the contact breaker and the other end is grounded. The ground is usually the engine itself. The secondary circuit is not electrically connected to the primary ignition circuit. It starts from the ground (usually the engine) and passes through the secondary winding, ' distributor, and spark plug to the ground. When the ignition switch is on, the current will flow through t