Subject: Automobile Engineering

Topic: Electrical System, Starting Systems & Alternator

Difficulty: Low

Electronic ignition system is the type of ignition system that uses electronic circuit, usually by transistors controlled by sensors to generate electronic pulses which in turn generate. Better spark that can even burn the lean mixture and provide better economy & lower emission.
Working:
To understand the working of the electronic ignition system let’s consider fig 11.1 in which all the components are connected in their working order.

When the driver switch ON the ignition switch in order to start a vehicle the current starts flowing from the battery through the ignition switch to the coil primary winding , which in turn starts the armature pick up coil to receive and send the voltages signals from the armature to the ignition module.

When the tooth of the rotating reluctor comes in front of the pickup coil, the voltage signal from pickup coil is sent to the electronics module which in turn senses the signals & steps the current to flow form.primary coil.

When the tooth of the rotating reluctor goes away from the pickup coil, the change in voltage signal is sent by pickup coil to the ignition module & a timing circuit inside ignition module turns ON the current flow.

A magnetic field is generated in the ignition coil due to this continuos make & break of the circuit.which induced an EME in secondary winding which increases the voltage upto 50,000 volts.

The high voltage is them sent to the distributor, which has the rotating rotor & distributor points which is set according to the ignition timing.

When the rotor comes in front of any of the distributor points the jumping of the voltage through the air gap from the rotor to the distributor point take place which is then sent to the adjacent spark plug through the high tension cable & a voltage difference is generated between the central electorade & ground electrode which is responsible for generating a spark at the tip of the spark plug & finally the combustion takes place.