Introduction

The purpose of ignition system is to create a spark that will ignite the fuel-air mixture in the cylinder of an engine. It must do that at exactly the right instant and do it at the rate of up to several times per minute for each cylinder of the engine. If the timing of the spark is off  by a small fraction of a second, the engine will run poorly or not run at all.The ignition is divided into two separate circuits, which are called the primary and secondary circuits.

Current from the battery flows to the ignition switch. When the switch is turned on, current flows through a resistor to the primary windings in the coil. From the primary coil windings, the current travels to the ignition module or contact points and on to ground where it turns to the battery via the metal parts.

Current flow through the primary windings builds up a magnetic field that surrounds the secondary windings. When the primary ignition control system breaks the primary circuit, the magnetic field around the secondary circuit. The primary circuit can broken by  an ignition module or by contact points. The electronic ignition module is signaled by one of three types of triggering devices.

Direct and integrated direct ignition systems do not use a distributor. Sensors are located on the crankshaft and/or camshaft. These systems use multiple coils. The secondary system consists of the coil secondary windings ,distributor cap, rotor, plug wires, and spark plugs. The plugs must last at least 15,000-30,000 miles and sometimes up to 100,000 miles. Most spark plugs contain a resistor for radio static suppression. The cap and rotor distribute the spark to the right plug. Plug wires are usually resistor types for radio interference suppression.

Initial timing is set by the use of a timing light or timing advance meter. The timing is advance by vacuum, centrifugal, or electronic means. Computerized ignition has the computer advance the spark after measuring all possible engine and vehicle variables.

This blog will Identify The next terms :

• The primary circuit of an ignition system.
• The secondary circuit of an ignition system.
• The construction of ignition components.
• The basic function and operation principles of ignition system.
• List the differences between a contact point and an electronic ignition system.
• The action of spark advance mechanisms.

The next figure shows two different types of ignition system. A-- A conventional contact or breaker point type. B--An electronic ignition system which incorporates a breaker-less style distributor.

References.

Auto Fundamental.

Advanced Automotive Fault Diagnosis 2nd Ed.

Automotive Computer Controlled Systems.

Familycar.com.

Wikipedia.com.

Carbible.com