Project - Analysis of a practical automotive wiring circuit

Ans 1.) Major elements in this circuit diagram are following :

a.) Battery

b.) Ignition system comprising of Ignition switch, Ignition coil, Circuit breaker, Distributor and spark plug

c.) Starter motor

d.) Generator (Also known as Alternator)

e.) Current and voltage regulator

f.) Ammeter for measuring current

g.) Fuse for safety of circuit

h.) Accessories like Horn, tail light, brake light, plate light, etc. and their switches

i.) Wire for each connection and completion of circuit including earthing

Ans 2.) Purpose and working of 3 elements :

1.) Battery : It is to store energy provided by Generator and provide the same energy to all the loads like Starter motor, ignition system, lamps, horn, fuel guage etc. when engine is off.

2.) Ammeter : It is for measuring current flowing in the circuit so as to ensure that the current is within safe limits.

3.) Fuse : Its a safety element. If the current in circuit goes beyond the rating of fuse, then a thin wire inside it melts and circuit breaks. It thus protects all the accesories and operator from any potential hazard.

4.) Generator : It charges the battery when the vehicle is running and provides the power to all the accesories as well.

Ans 3.) If the total load current from battery is 10A, then the fuse rating should be more than that but closer to it. So, a fuse with rating of 14A to 15A will be recommended depending upon its availability.

Ans 4.) Load = 500W

Let we take a battery with voltage 12V.

Then current to be provided by battery = Power/Voltage

= 500/12

= 41.66 A

Now let we want to run this battery for 5 hours, then battery capacity should be = 41.66 x 5

= 208.3 ≈ 210Ah

Kindly note that here we have not assumed any power losses and assumed efficiency of battery as 100%. The required battery capacity will increase in case they are also considered.

Ans 5.) All the accessories like Tail lamp, horn, ignition switch etc. are connected in parallel to each other so as to ensure that voltage across these loads is same. They will withdraw current as per their resistance values and power requirements.

Also, they can be switched on/off independently.

Also, starter motor is connected in parallel to ensure that voltage acorss it is samea as battery and it withdraws currenta as per its requirement.

Ans 6.) Fuse is connected in series in circuit so as to ensure that all the current provided by battery goes through it before going to any accessory for the safety of all accessories and operator.

Also, Ammeter is connected in series for measuring current flowing through the circuit.

Also, all the accessories like lamps, horn etc. are in series combination with their switches.