Project - Analysis of a practical automotive wiring circuit

1) The major elements in the automotive wiring :

• Battery
• Generator
• Fuse
• Starter
• Ammeter
• Ligth switch
• Lamp
• Ignition switch
• Ignition coil
• Foot selector switch
• Gas tank unit
• Horn
• Horn botton
• Circuit breaker
• Ditributor
• Current regulator and Voltage regulator
• Grounding
• Tail stop

2)

Generator:

A generator which is an indispensable part of every car consists of a rotor a stator a rectifier and an end cap. it is not only an application. in the car in the national defense science and technology,industrial production and other fields also has a very wide range of application.

At first when the switch is closed the battery to run follow the battery cathode to charging indicator to regulator contact to excitation to grounding to battery to battery negative circuit makes the battery discharge and the indicator light.

But with the engin start the generator speed gradually increased to its output voltage is equal to the battery voltage the car power supply state conversion , converted to the generator for the car to provide energy , and indicator light off. the external circuit through the brush makes the excition winding power, generate magneticfield the claw pole magnetization to the N pole and S pole , so the rotor rotation process, the magnetic flux alternately in the stator winding resulting in alternately induced electeomotive force.it is can be a normal power generator.

Ammeter:

The working process of ammeter is based on the magnetic effect of current , its principle is that the resistance must be low . ammeter cinsists of a coil of wire and a fixed permanent magnet . hence a ammeter can be never connected un a parallel connection.

Battery:

The principle behind the lithium-ion battery is to circulate electrons by creating a difference in potential between two electrodes, one negative and other positive, that are immersed in a conductive ionic liquid called the electrolyte.

3) Fuse rating :

A fues is an electrical safety device that operates to provide over current flow an a electric circuit.

Fues rating will be calculated based on the power and voltage the load works.

P=V/A

P=power

V=voltage

A=current

Here the total load is 10A normally fuse rating wil more than the maximum ampere used by the load we can take the fuse rating as 13-15A fuse rating.

4) given data:

load=500W

find:

V=voltage

Ah=capacity

solution:

E=P X T

E= energy

P= power

T=time

500W load is need for the system for 1 hour

E=P X T

E= 500W X 1 h

E=500Wh

assume 12 V is recommended for this operation

battery capacity Q=E/V

Q- Battery capacity (Ah)

E= Energy

V= Voltage

Q=E/V

Q=500/12

Q= 41.6Ah

5) Horn button :

Horn button with horns is connected in parallel,because it is operate in same voltages but in different currents.

Light switch:

Ligth switch is connected with parallel to all the lights, because each light requires different power.

6) Battery and ammeter:

The battery is connected to the ammeter in series to measure the current from the battery,in series connection current in same.

Battery and starter:

The starter are connected in series because the starter needs the direct and hight current from the battery.