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IGNITION SYSTEM OF I.C ENGINES

 In I.C Engines, the ignition of air - fuel mixture should take place at the end of compression stroke. stroke. It ensures efficient and smooth running of an engine. There are mainly two different types of ignition used in I.C engines.

1. Compression Ignition,  and 

2. Spark Ignition.

I) COMPRESSION IGNITION :



This system is used in heavy oil engines working on diesel cycle. In these engines, fresh air is drawn into the engine cylinder during suction stroke. This is air compressed to a high compression ratio (12 to 18) during compression stroke. The air pressure at the end of compression is about 3500 k N/m2. The temperature at the end of compression is about 600*C . At the compression stroke, the fuel is injected into the engine cylinder in the form of fine spray. The temperature of the air is higher than the self- ignition temperature of the fuel injected. Hence, the fuel air mixture is ignited simultaneously.

In Diesel Engines, The ignition of fuel air mixture takes place due to the high pressure and temperature of the air. Hence, they are known as " Compression Ignition C.I Engines."

II) SPARK IGNITION :

   Spark Ignition is mostly used in gas engines, petrol engines and light oil engines working on Otto Cycle. In this system the fuel - air mixture is ignited by a high tension electric spark. Hence , they are known as spark Ignition (S.I) Engines. There are different types of spark ignition systems used in Otto Cycle Engines.



a) Coil Ignition System. 

b) Magneto Ignition System.'

c) Electronic Ignition System.

d) Transistorized Ignition System 

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