Project - Analysis of a practical automotive wiring circuit
1) The major elements in the above automotive wiring diagram are as follows
a) Battery System
b) Starter System
c) Generator System
d) Ignition System
e) Ground/Earthing System
f) Indication lights, Head Lamps etc.
g) Protection System - i.e. Fuse
h) Horns
i) Selector Switches, Light Switches etc.
j) Gas Tank Unit with Fuel Gauge
2)
a) Battery System - A battery is device that can store and release energy as per the requirement. It converts chemical energy to electrical energy and releases electricity. It contains basically of three components - an anode (+ve), a cathode (-ve) and the electrolyte. When the two terminals of the battery are connected, electrons flow from the anode to the cathode and into the circuit. In a car, the battery is used to run the electrical system while the car alternator or dynamo recharges the battery while the car is running
b) Ignition System - It is used to provide the spark for a IC engine. The Ignition system is input with 12 V supply from the battery. With the help of Ignition coils which are basically step up transformers, the 12V is converted to 20,000 to 50,000V. The high voltage supply with the help of switch coils and timing controllers provide the spark to the different spark plugs of the engine.
c) Starter System - It initiates the engine of the cat. When you start the car by putting the key in the ignition switch, you are passing to the motor of the starter. This starts the engine causing the piston to move. This causes vacuum inside the cylinder causing air and fuel to be sucked in. With the help of the ignition system, fuel mixture burns and the engine starts.
3) For a total load of 10A of the battery, the recommended fuse should be 15A. It is high enough to allow small fluctuations in current without shorting and low enough that a severe spike will cause the fuse to short.
4)
Total Power is 500W.
Battery capacity is 12V
Energy Required for the battery to operate for 1h E = Power * Time = 500W * 1h = 500Wh
Battery Capacity Q (Ah) = Energy/Voltage
Q = 500/12 = 41.67 Ah
Recommended Battery is 12 V and 45 Ah
5) The head lamps and the horn are connected in parallel. In a parallel connection, the components share two common nodes. Hence, the potential between the two nodes for all components connected in parallel is the same. As these components operate at the same voltage, a parallel connection is suitable for this purpose. It is also useful as a failure of one of these devices doesnt affect the other device and they can be operated individually
6) The Ammeter and Battery are connected in series. In a series circuit, all components are connected sharing only one common node. In a series connection, the current remains constant. An ammeter is a device used to measure the current in the circuit. Hence, the ammeter is connected in series to measure the maximum current in the circuit.