Project - Analysis of a practical automotive wiring circuit

Q1. Identify each of the major elements in the above automotive wiring diagram.

Solution: Above diagram is of automotive wiring circuit diagram, which consists of.

• Battery
• Starter
• Breaker
• Ignition coil
• Distributor
• Generator
• Junction Block
• Scaled Beam
• Horn
• Parking lamp
• Current and Voltage Regulator
• Foot Selector Switch
• Ammeter
• Horn Button
• Dome Light Switch
• Tail Stop
• Light Switch

Q2. Explain the purpose and working of any three elements briefly?

Solution:

1) Battery:

• Purpose: The first purpose of an auto battery is to provide power for starting your vehicle; it also acts as a surge protector for the car's computer and provides power for short-term use of things like lights, stereo, GPS or wipers when the engine is off. The car battery is part of the starting system.
• Working: Battery is DC system. Hence battery means storage of energy which latter can be used in the car. Hence an AC current is converted to DC and it is stored in the battery. When we give ignition i.e when we give order to start the engine (stator) at that time energy stored in the battery is used to start the starter or to start the vehicle. Battery is connected to starter and also there is ammeter attached to check the current in the battery.

2) Ignition Coil:

• Purpose: The ignition coil acts like a transformer. By means of two coils, one inside the other, the ignition coil transforms the electrical energy from the vehicle battery into high voltage, saves it briefly and then emits it as a high voltage current pulse to the spark plug.
• Working: Ignition coil is used to give spark, the electrical energy (voltage) from the battery is converted to high voltage current and that current is used to spark the plug. Basically the voltage received from the battery is low and for ignition high voltage is required and hence Ignition coil is used.

3) Generator:

• Purpose: The function of the generator is to supply current for the operation of the ignition system, the lighting system, and all other electrical parts when the engine is running and to replenish the battery after it has supplied current for starting and other purposes when the engine is at rest.
• Working: To start the starter we require the battery energy, what if the battery power is almost going to finish how to charge the battery, it is not always possible to charge the battery from external source, hence when the vehicle is running the work of alternator is to charge the battery regularly and supply power to the system again.

4) Distributor:

• Purpose: A distributor is an enclosed rotating shaft used in spark-ignition internal combustion engines that have mechanically-timed ignition. The distributor's main function is to route secondary, or high voltage, current from the ignition coil to the spark plugs in the correct firing order, and for the correct amount of time.
• Working: There is sparking going on in the engine, so the work of distributor is to give correct amount of spark and the timing for the sparking.

Q3. If the total load is 10A from battery, what should be the fuse rating?

Solution:

The fuse rating is always greater than load current.

Hence for 10A battery 15A fuse rating is used.

4. If 500W is the load, what is the voltage and capacity of battery you recommend?

Solution:

A normal battery has a voltage around 12V and to find capacity we will be using power equation i.e.

P = V x I,

P = 500W

V =12V

I = 500/12

I = 41.6 A

Hence Capacity is 41.6 Ah

5. Identify any two elements which are connected parallel to each other. Why they are connected in parallel?

Solution:

1) Car Bulbs (Interior & Exterior)

2) Horn

Because we want voltage to be same. Voltage should be same that's the main reason. Because if the same voltage is supplied to both the bulb then only both will blow at same time.

Hence, Voltage should be same for Parallel Connection

6. Identify any two elements which are connected in series. Why they are connected in series?

Solution:

1) Fuse

2) Ammeter

Reason behind connecting them in series is because the current should be same when applied to the above system. If the current supplied is less then that may hamper the fuse system

Hence, Current should be same for Series Connection.