Electrical System

Electrical System ...How does it Work?

The electrical system of the automobile was, at first limited to the ignition equipment. However, electric lights and horns began to replace the kerosene and acetylene lights and the bulb horns with the advent of the electric starter on a 1912 model. Electrification was rapid and complete, and, by 1930, six-volt systems were standard everywhere. The electrical system consists of a storage battery, generator, starting (cranking) motor, lighting system, ignition system, and various accessories and controls.


The ignition system consists of the spark plugs, coil, distributor, and battery, and provides the spark to ignite the air-fuel mixture in the cylinders of the engine. In order to jump the gap between the electrodes of the spark plugs, the 12-volt potential of the electrical system must be stepped up to about 20,000 volts. This happens with the aid of a circuit that starts with the battery, one side of which is grounded on the chasis and leads through the ignition switch to the primary winding of the ignition coil and back to the ground through an interrupter switch. A high voltage id induced across the secondary of the coil by interrupting the primary circuit. The high-voltage secondary terminal of the coil leads to a distributor that acts as a rotary switch, alternately connecting the coil to each of the wires leading to the spark plugs.


The generator is the basic source of energy for the various electrical devices of the automobile. An alternator that is belt-driven from the engine crankshaft is also used at times. The design is usually an alternating-current type with built-in rectifiers and a voltage regulator to match the generator output to the electric load and also to the charging requirements of the battery, regardless of engine speed.

To store excess output of the generator, a lead-acid battery is used which serves as a reservoir. Energy for the starting motor is thus made available along with power for operating other electric devices when the engine is not running or when the generator speed is not sufficiently high to carry the load.

The starting motor then drives a small spur gear, which is so arranged that it automatically moves into mesh with gear teeth on the rim of the flywheel as the starting-motor armature begins to turn. As soon as the engine starts, the gear is disengaged, which prevents the starting motor from getting damaged due to overspeeding. The starting motor is designed for high current consumption and delivers considerable power for its size for a limited time.



Ignition System

BATTERY
The battery is the backbone of your vehicle’s electrical system. It supplies power to the starter and ignition system. It also delivers the extra power needed when the electrical load exceeds the alternator’s supply.
You should have your battery and it’s connections checked at every oil change.

If your battery is more than three years old, it’s a good idea to think about replacing it.


STARTER
The starter cranks the engine when the ignition switch is turned on. It’s located on the back of the engine or the front of the transmission.











Charging System

ALTERNATOR
The alternator is your car’s electrical charger. It generates direct current for recharging the battery. It also helps power the other electrical loads of your car. It’s various parts are contained in an aluminum housing.


An alternator that is belt-driven from the engine crankshaft is also used at times. The design is usually an alternating-current type with built-in rectifiers and a voltage regulator to match the generator output to the electric load and also to the charging requirements of the battery, regardless of engine speed.