19 March 2016

What is ignition system? | Purpose | Types

An ignition system generates the electrical charge between the two electrodes of the spark plug to ignite a fuel-air mixture in the spark-ignition internal combustion engine.

Purpose of ignition system: 

To generate a very high voltage from the 12-volt battery of the car and send this to each spark plug. In short to initiate flame propagation. 

Explain the ignition system: 

The ignition system can be treated as a balance of energy between that provided by an external source or released by the chemical reaction so it obeys the law of conservation of energy. 

Ignition system should provide a sufficiently large voltage across the spark plug electrodes to affect the spark discharge and duration at the appropriate time. 

To obtain maximum power from an engine, the compressed mixture delivers its maximum pressure at the time when the piston is about to its downward stroke and is very close to TDC this is the reason why Ignition timing is a very important parameter in the ignition system.

Types of ignition system: 

The ignition system classified depending upon how the primary energy for operating the circuit is made available as :
  • Battery Ignition System
  • Magneto Ignition System
In modern automobiles the following two types are in common use :
  • Transistorized coil ignition system
  • Capacitive discharge ignition system