Aircraft Ignition system SNS COLLEGE OF TECHNOLOGY Aircraft Ignition system SNS COLLEGE OF TECHNOLOGY 5/15/2018

SNS COLLEGE OF TECHNOLOGY Ignition system An ignition system is a system used for igniting a fuel-air mixture The function of the ignition system is to provide an electrical spark to ignite the fuel/air mixture in the cylinders. 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY The ignition system of the engine is completely separate from the airplane's electrical system. 5/15/2018 SNS COLLEGE OF TECHNOLOGY

VARIOUS COMPONENTS OF IGNITION SYSTEM IGNITION SWITCH MAGNETO DISTRIBUTOR TRANSFORMER SPARK PLUG 5/15/2018 SNS COLLEGE OF TECHNOLOGY

BATTERY IGNITION SYSTEM: 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY Few aircraft and most automobiles use a battery ignition system which has a battery or Generator rather than a magneto as its source of energy. 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY In battery ignition system, a cam is driven by the engine opens a set of points to interrupt the flow of current in primary circuit 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY The magnetic field induces a high voltage in the secondary of the ignition coil, which is directed by a distributor to the proper cylinder. 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY MAGNETO IGNITION SYSTEM 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY The magneto type ignition system is used on most reciprocating aircraft engines. Magnetos are engine driven self-contained units supplying electrical current without using an external source of current. However, before they can produce current the magnetos must be actuated as the engine crankshaft is rotated by some other means. 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY It is superior to battery ignition because produces a hotter spark at high engine speeds It is self contained unit, not dependent on any external source of electrical energy It produces a high voltage in spark plug gap in each cylinder 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY 5/15/2018 SNS COLLEGE OF TECHNOLOGY

CLASSIFICATIION OF MAGNETO IGNITION SYSTEM It can be classified into two types Low tension magneto system High tension magneto system 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY Modern airplane engines are required by to have a dual ignition system Two separate magnetos to supply the electric current to the two spark plugs contained in each cylinder. One magneto system supplies the current to one set of plugs; the second magneto system supplies the current to the other set of plugs. For that reason the ignition switch has four positions: 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY OFF, L, R, and BOTH With the switch in the "L" or "R" position. only one magneto is supplying current and only one set of spark plugs in each cylinder is firing. With the switch in the BOTH position, both magnetos are supplying current and both spark plugs are firing. 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY SPARK PLUG 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY PURPOSE IS TO CONDUCT A SHORT IMPULSE OF HIGH VOLTAGE THROUGH THE WALL OF THE COMBUSTION CHAMBER 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY MAIN COMPONENTS ARE OUTER SHELL INSULATOR ELECTRODE 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY 5/15/2018 SNS COLLEGE OF TECHNOLOGY

SNS COLLEGE OF TECHNOLOGY 5/15/2018 SNS COLLEGE OF TECHNOLOGY