Project - Analysis of a practical automotive wiring circuit

1.

Battery

Starter

Generator

Breaker

Distributor

Ignition coil

Horn

Head lamp

Parking lamp

Foot selection switch

Horn button 

Stop light switch

Beam switch

Ammeter

Fuel gauge

Ignition switch

2.

Battery:

Purpose: The battery in an automotive system serves as a storage device for electrical energy. It provides the initial power needed to start the engine, and it supplies electricity to various electrical components when the engine is not running.

Working: The battery stores electrical energy in the form of chemical energy. When you turn the key to start the engine, the battery sends a large burst of electrical energy to the starter motor, which cranks the engine and gets it running. When the engine is off, the battery powers accessories like lights, radio, and electronics.

Starter Motor:

Purpose: The starter motor's main purpose is to crank the engine's internal components, such as the pistons, so that the engine can begin running on its own.

Working: When you turn the ignition key, an electrical current from the battery flows to the starter motor. The starter motor then engages with the engine's flywheel (or flexplate), which is connected to the crankshaft. As the starter motor turns, it rotates the engine's internal components, allowing the engine to suck in air and fuel and initiate the combustion process.

Generator (Alternator):

Purpose: The generator, often called an alternator in modern vehicles, serves to charge the battery and provide electrical power to the vehicle's electrical system while the engine is running.

Working: When the engine is running, the generator (alternator) is driven by a belt connected to the engine's crankshaft. It generates electricity by using the principle of electromagnetic induction. As the alternator spins, it produces alternating current (AC), which is then converted into direct current (DC) by a rectifier. The DC electrical energy is used to charge the battery and supply power to the vehicle's lights, ignition system, electronics, and other electrical components. The alternator also maintains the battery's charge so that it's ready to provide power for starting the engine the next time you turn the key.

3.

When determining the appropriate fuse rating for a circuit powered by a battery, the fuse should be rated slightly higher than the maximum expected current draw to protect the circuit without being too sensitive. In your case, if the total load is 10 amperes (A) from the battery, you should use a fuse with a rating slightly higher than 10A.

Typically, you would choose a fuse rating that is 15-20% higher than the maximum expected current. This provides some margin for temporary current spikes or variations in the load.

So, for a 10A load, you might choose a fuse with a rating of 12A or 13A. However, standard fuse ratings commonly available may not include these exact values, so you would typically round up to the nearest standard fuse rating, which could be 15A in this case.

4.

Current (A) = Power (W) / Voltage (V)

In this case, Current (A) = 500W / 12V = 41.67A (rounded up to the nearest standard fuse rating).

Now that you know your load will draw approximately 41.67A, you should choose a battery with a capacity (measured in ampere-hours, Ah) that can provide power for your load for the desired duration. The capacity of the battery depends on how long you want your load to run before the battery needs recharging or replacing.

For example, if you want your 500W load to run for 5 hours without recharging, you can calculate the required battery capacity as follows:

Battery Capacity (Ah) = Current (A) × Time (h)

Battery Capacity (Ah) = 41.67A × 5h = 208.35Ah

So, you would need a battery with a capacity of approximately 208.35 ampere-hours to power a 500W load for 5 hours using a 12V battery.

5.

Battery & Starter

A vehicle's starter motor requires a significant amount of electrical power, typically at a voltage of 12V for most automotive systems. Automotive batteries are designed to provide this voltage. Connecting them in parallel ensures that the starter motor receives the necessary voltage to function correctly.

6.

Fuse and tail stop

Fuses are safety devices designed to protect electrical circuits from excessive current flow. They are connected in series with the circuit they are protecting. When the current in the circuit exceeds the fuse's rated value, the fuse wire melts, breaking the circuit and preventing further current flow. This series connection