Project - Analysis of a practical automotive wiring circuit

Q1 Answer - Major elements in the above automotive wiring diagram are -

• Battery
• Ammeter
• Startor
• Generator
• Distributor
• Breaker
• Current and Voltage regulator
• Junction block
• Fuse
• Ignition coil
• Horn and Horn button
• Light Switch
• Tail stop
• Stop light switch
• Parking Lamp
• Dome light and dome light switch
• Gas tank unit

Q2 Answer -

1. Battery

Purpose - In automobile the first purpose of battery is to provide power for starting your vehicle and to provide power to loads when vehicle is idle in close battery circuit.

Working - A battery is a collection of cells which coverts chemical energy into electrical energy. Each cells consists of an anode , a cathode and an electrolyte. When the terminal of a cell are connected across an electric device results in the flow of electricty in the circuit. Celss can be connected in either series or parallel connection to obtain the desired output.

2. Fuse

Purpose - Its purpose is to provide protection against the overflow of current in an electrical circuit.

Working - A fuse consists of a piece of wire made of a metal or an alloy of an appropriate melting point, If a current larger than the specified value flows through the circuit, the temperature of the fuse wire increases. This melts the fuse wire and breaks the circuit.

3. Generator

Purpose - Its purpose is to generate electricity to charge the battery while vehicle's engine is running.

Working - It works on the principle of electromagnetic induction and convert mechanical rotational energy from engine to electrical energy.

Q3 Answer - If the total load is 10A from battery then the fuse rating should be 125-130% of the load. According to this fuse rating should be 12.5-13A but next available standard size is 15A. So 15A should be fuse rating.

Q4 Solution -

Given that

Total load = 500W ( we can write 500W-hr)

To find , Capacity of the battery = ?

we can take battery voltage, V = 12V

So, Capacity of the battery = 500/12

= 41.67 Ah

Hence 41.67Ah capacity of battery can be recommended.

Q5 Answer - Horn and parking lamp are connected parallel to each other because this allow us to connect the both element in their individual switch.

Q6 Answer - Horn button and Horn are connected in series connection because this allows us to connect the element in common switch.