Today we will discuss about battery ignition system main parts, function, working, advantages and Disadvantages. Most of SI engine used. Battery Ignition System is used in automobile to produce spark in the spark plug for the combustion of fuel in the I.C. engine. Here the main. UNIT 4 IGNITION SYSTEMS. Structure. Introduction. Objectives. Ignition System Types. Comparison between Battery and Magneto Ignition System.
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The ignition system provides a spark of sufficient Battery ignition system. 2. Battery.: provides the power to run the system. Ignition switch: allows the driver to turn the system on and off . chancromaslodis.ga The primary circuit consists of: • Battery - provides the power to run the system. • Ignition Switch - allows the driver to turn the system on and off. • Breaker switch. Most of the modern spark-ignition engines use Battery Ignition System. The essential components are a battery, ignition switch, ballast resistor.
Ballast resistor It is connected in series with primary winding to regulate current in primary winding.
It is used to prevent injury due to overheating of ignition coil. It controls the current passes through primary winding. It is made by iron. Iron has property of increase electrical resistance rapidly by increase in temperature at certain limit.
Battery Ignition System
This additional resistance resists flowing current which control the temperature of ignition coil. Ignition coil Ignition coil is the main body of battery ignition system. The purpose of ignition coil to step up the battery voltage 6 or 12 to a high voltage, which is sufficient to produce spark at spark plug. It consist a magnetic core or soft wire or sheet, and two electrical winding called primary winding and secondary winding.
The primary winding has generally turn and the end are connected to exterior terminal. The secondary has almost turns of copper wire which is insulated to withstand with high voltage. It is located inside the primary winding and its one end connected to secondary winding and other end is grounded either to primary winding or to the metal case.
This entire unit is enclosed in a metal container which makes it a compact unit.
Contact breaker This is a mechanical device making and braking the primary circuit to ignition coil. When the points are closed current flow in ignition coil and when it open, flow of current stopped. Capacitor It is a simple electrical capacitor in which two metal plate are separated by an insulating material with a distance. Commonly air is used as insulating material but for particular technical requirement some high quality insulating material is used.
Distributor Distributor is used in multi cylinder engine to regulate spark in each spark plug at correct sequence. It distribute ignition surge in individual spark plug in correct sequence. There are two types of distributor. One is known as carbon brush type and the other one is gap type.
In carbon brush type carbon brush carried by the rotor arm sliding over the metallic segment embedded into the distributor cap or molded insulating material. This makes electric connection or secondary winding with spark plug.
Battery ignition system:
In gap type distributor electrode of rotor arm pass close to but does not make contact with the distributor cap. So there is no wear of electrode. Spark Plug A spark plug generally has two electrodes which are separated with each other. A high potential discharge flow through it which generate spark and ignite the combustion mixture in cylinder. It mainly consist two electrodes a steel shell and an insulator.
The central electrode connected with the supply of ignition coil. It is well insulated with the outer steel shell which is grounded. There is a small air gap between steel shell and central electrode, between which spark is generated.
The electrode usually made by high nickel alloy so it can withstand with high temperature and corrosion resistance. Working of Battery Ignition System: In the battery ignition system ignition coil stores the energy in form of magnetic field and deliver it at the instant of ignition, in form of high voltage current with high tension wire to correct spark plug.
The diagram of four cylinder battery ignition system is as follow.
First low voltage current flow form battery to the primary coil through ignition switch and ballast resistor. Ballast resistor regulates the temperature of ignition coil by regulating current passing form it.
The ignition capacitor connected in parallel with contact breaker.
Schematic diagram of Battery Ignition System When the ignition switch and the breaker points are closed a low-voltage current flows from the battery through the primary circuit and builts up a magnetic field around the soft iron core of the ignition coil. When the breaker points are opened by the action of the cam on the distributor shaft, the primary circuit is broken and the magnetic field begins to collapse, an induced current from the collapsing magnetic field flows in the same direction in the primary circuit as the battery current and charges the condenser which acts as a reservoir for the flowing current due to a rapidly collapsing magnetic field, high voltage is induced in the primary it might be as high as volts and even higher in the secondary 10, to 20, volts.
The high voltage in the secondary passes through the distributor rotor to one of the spark plug leads and into the spark plug. As soon as sufficient voltage is built up in the secondary to overcome the resistance of a spark plug, the spark arcs across the gap and the ignition of the combustible charge in the cylinder takes place.
The induced current in the primary to overcome the resistance of a spark across the gap and the ignition of the combustible charge in the cylinder takes place.
The induced current is the primary, as it was pointed out above flows in the same direction as it did before the breaker points opened up and charges the condenser.
This rapid discharge of condense produces directional oscillation in the current flow in the primary circuit. This oscillation is weekend with every succeeding reversal in the current flow until the original potentials and the direction of current flow the primary circuit are established. The discharge of condenser by itself does not produce the spark, but only hastens the collapse of the magnetic field around the soft iron core.
The condenser, which has a capacitance range from 0. If the condenser is too small or too large, the breaker points will lead to excessive pitting will result the breaker points and the distributor must be carefully synchronized with the crankshaft of the engine to give the proper timing of the spark in each of the cylinders.
The breaker is often refereed to as the timer, since the time or point in the cycle that the spark occurs depends upon the time of opening of the breaker points. The spark plug leads are called the ignition harness.When the points are closed, the current flows through the primary circuit and it stops if open.
How Battery Ignition System Works?
Passenger cars, light truck, motorcycles and large stationary engines are fitted with this system. This allows the coil a longer time to accumulate a charge between sparks, and therefore a higher energy spark. However, for the low speed and the low compression of such early engines, this imprecise timing was acceptable.
This makes electric connection or secondary winding with spark plug.
How Battery Ignition System Works?
And other end is connected with the contact breaker as well as secondary winding. Inductive discharge ignition. As the rotor rotates, it presses and opens the contact breaker point.
Initial expenditure is less and it has low maintenance cost.