BATTERY IGNITION SYSTEM OR COIL SYSTEM

It is employed in Petrol Engines And used in Automobiles.

Construction :

It consists of a battery , ignition coil, condenser, contact breaker, distributor and spark plugs.

Working :

The Ignition Switch is switched on and the engine is cranked. The cranking of the engine opens and closes the contact breaker points through a cam.

When the contact breaker points are closed:

1. The current flows from the battery to the contact breaker points through the switch and primary winding and then returns to battery through the earth.

2. This current builds up a magnetic field in the primary winding of the ignition coil.

3. When the primary current is at the highest peak, the contact breaker points will be opened by the cam.

When the contact breaker points are opened :

1. The magnetic field set up in the primary winding is suddenly collapsed.

2. A high voltage (15000 volts) is generated in the secondary winding of the ignition coil.

3. The high voltage is directed to the rotor of the distributor.

4. The rotor directs this high voltage to the individual spark plugs in the sequence of the firing order of the engine.

5. This high voltage tries to cross the spark plug gap ( 0.45 to 0.6 mm) and the spark is produced. This spark ignites the fuel - air mixture.

Advantages :

* It provides better spark at low speeds of the engine during starting and idling due to availability of maximum current throughout the engine speed range.

* The Initial cost is low as compared with magneto Ignition System.

* The maintenance cost is negligible except battery.

* Spark efficiency remains unaffected by various positions of the timing control mechanism.

Disadvantages :

* Frequent battery down occurs when the engine is not in use continuously. This causes starting trouble.

* The weight is greater than magneto ignition system.

* Wiring Mechanism is more complicated.

Comments

ELECTRICAL COMPARATORS AND ITS WORKING

Electrical Comparators are used as a means of detecting and amplifying small movements of a work contacting elements. An electrical comparator consists essentially of a pick-up head or transducer for converting a displacement into a corresponding change in current and a meter or recorder connected in the circuit to indicate the electrical change, calibrated to show in terms of displacement. Generally, an amplifier is needed to provide the requisite sensitivity and to match the characteristics of different parts of the circuit. Electrical comparators can be classified according to the electrical principle used in the pick-up head. Most of the comparators use either a differential transformer, an inductance bridge, a strain gauge or a capacitor as a means of detecting movement of the gauging element. There are different types of electrical comparators. One kind called an electrolimit gauge is used to check or measure the outside diameter of a roll. The objec...

SIMPLE CARBURETOR - CONSTRUCTION AND WORKING

CONSTRUCTION OF SIMPLE CARBURETOR : The main Components of Simple Carburetor are : Float Chamber, float, nozzle, venturi, throttle valve, inlet valve, and metering jet . In the float chamber, a constant level of petrol is maintained by the float and a needle valve. The float chamber is ventilated to atmosphere. This is used to maintain atmospheric pressure inside the chamber. The float which is normally a metallic hollow cylinder rises and closes the inlet valve as the fuel level in the float chamber increases to certain level. The mixing chamber contains venturi, nozzle and throttle valve. The venturi tube is fitted with the inlet manifold. This tube has a narrow opening called venturi. A nozzle is provided just below the centre of this venturi. The nozzle keeps the same level of petrol as that of the level in the float chamber. The mixing chamber has two butterfly valves. One is to allow air into the mixing chamber known as choke valve. The other is to al...

TOP POLLUTION RECORDED IN WORLD

CHERNOBYL NUCLEAR DISASTER (NUCLEAR POLLUTION) : In April 26,1986, the melt down of the Chernobyl nuclear reactor , in Russia, has leaked out the radioactive rays and radioactive materials. Effects : 1. In this Pollution nearly 2000 persons have been killed by the accident. 2. People suffered due to the illness such as, degeneration of the cells, severe bleeding, anemia, skin cancer. 3. Animals, Plants are also affected by nuclear radiation. MINAMATA EPIDEMIC (1953) : MARINE POLLUTION ( CASE STUDY ) Minamata is a small coastal village in Japan. The Chisso Chemical Company , which produces vinyl polymer plastics used organomercurial compound. The industry released its effluent into Minamata sea. The effluent containing mercury ions is converted into methyl mercury, which is highly toxic. The marine organisms like phytoplankton and zoo-planktons easily absorb the toxic methyl mercury compound. These organisms are consumed by small fishes and these are in ...

Mechinopedia For Mechanical Engineers

Search This Blog