Project - Analysis of a practical automotive wiring circuit

1. Major elements in the given automotive wiring diagram are
Battery, Motor(Starter), Generator, Switch, Inductor(Coil), Safety Devices(Breakers and Fuses), Distributors, Sensors.

2.

Battery- Depending on the propulsion method, battery can differ. For traditional ICE Vehicles, batteries are used to power the accessories and provide energy to the starter motor of the vehicle. For an EV, the prime mover is a motor and this motor is powered by a high capacity battery. This would be a different battery compared to ICE batteries. In the given diagram, the battery provides electric power to almost all the components in the circuit including lights, horn and starter motor.

Motor- Motor is the prime mover in an electric vehicle. The motor provides a torque when supplied with electric energy which in turn drives the wheels. In the given diagram, the motor is a starter motor. The starter motor is used to start the engine. Once the ignition switch is active, the current voltage regulator sends electric charge to the starter motor which starts rotating and starts the engine accordingly.

Fuse- Fuse is a safety device. When the current flowing through a circuit is high, the metal inside the fuse breaks contact and the closed circuit becomes an open circuit. In the above circuit, almost all the elements that has an electric current flow is connected with a fuse. If there is anything wrong with any of these circuits or elements in them, the excessive current will be sensed by the fuse and the metal wire breaks after which current flow stops.

3. If the total load is 10A from the battery, ideally a fuse should be selected by adding 10% to maximum current and selecting the next nearest fuse rating. So when total load from battery is 10A, adding 10% makes it 11A. The next available fuse rating would be of 15A.

4. Assuming this is continued from the previous question, Current would be 10A.

Power of the load is 500W.

Voltage of the Load(V) = Power(W) / Current(A)

= 500 / 10

= 50 V

Capacity= 10A x 5h(example) = 50Ah = 500W x 5 = 2500Wh

Assuming the load needs to work for atleast 5 hours, the battery can be a 50Ah battery or a 2.5kWh battery.

5. The tail light and the plate lights are connected in parallel. Both these elements have one end connected to the light switch and other end connected to the ground. Any device with same nodes on either sides should be connected in parallel. These are connected in parallel because the tail lights and plate light need to be turned on simultaneously and same voltage is supposed to be supplied to them.

6. The ignition coil and distributor are connected in series. This is because there is only one common node between them and other node is connected to other elements. Ignition coil and distributor are connected in series because all of the electric energy generated by the coil should reach the distributor without any losses which would enable the distributor to spark the plugs according to the firing order.