In automobiles, especially the modern ones, varieties of parts are electronics and operate electrically. Well, charging systems are the basic electrical system in a vehicle which include an alternator, battery, and voltage regulator.
These components are a source of power to other electrical components in the vehicle.
Although voltage regulators are included in the alternator which serves as energy converters. There are tons of electrical components that rely on the electrical system of the vehicle. I guess that is our purpose here, so let’s dive in!
Today you’ll get to know the definition, applications, components, diagram, and working of the electrical system of a vehicle. you’ll also get to know its advantages and disadvantages.
What Is the Car’s Electrical System?
Car electrical systems are electrically controlled devices in a vehicle, they receive energy from the battery and return it to the battery through the hearth. The charging system comprises of alternator and battery.
This battery is used to power the starter motor and helps the engine to start running while the alternator is used to charge the battery and other electrical components in the vehicle.
Apart from this charging, some automotive vehicles are designed with magneto ignition which generates power that powers a spark plug in the combustion chambers. It’s also used to power some electrical components, which helps to save battery power.
Although some ignition system depends on the battery’s power. All electrical circuits in vehicles are opened and closed either by switches or relays and fuses are used to prevent them from overloads.
Applications
The primary use of the electrical system is to power all electrical and electronic devices in a vehicle. starting from the electrical motor, sensors, gauges, heating element, headlights, brake and trafficator lights, radio, television, air conditioning system, blowers, interior lights, refrigerator system, ignition system, etc.
All these components receive power from a battery and the battery is charged by the alternator. Note, when the engine is running all electrical devices are powered with the alternator regulator’s power.
This is because the alternator output is greater than the battery current when the engine is running.
Functions
Below are the functions of the vehicle’s electrical system:
- The primary function of a vehicle’s electrical system is to generate, store, and supply electrical current to the various electrical devices in a car.
- It operates all electrical parts/components of a vehicle.
- Again, the vehicle’s electrical systems help to keep devices in good working condition as they can achieve some features.
Components of vehicle electrical system
This complex network has several key components, and each has a task or tasks to manage. While there are others, these are six of the most notable parts to consider in a standard car electrical system.
- Battery. A car battery is a storage device that powers the electrical system whenever the engine is off, and its main role is to deliver the power necessary to start the engine. It’s also a reserve energy source when the engine is running, which is also when it replenishes its charge. The battery consists of six cells, each slightly more than two volts each. They store electrical energy by converting it to chemical energy, then converting it back when it’s demanded by systems in the car.
- Alternator. The alternator, also more accurately known as a generator, amplifies a tiny charge from the battery into a high-amperage current whenever the engine is running, using the principles of electromagnetism. The power it generates is used to power systems while the car is on, and excess energy is delivered to the battery to top it up so it can start the engine the next time it needs to.
- Starter motor. The only job the starter motor performs is to initiate the combustion process by moving the crankshaft from a stop. It spins the flywheel or flexplate, employing gear reduction to make the most of its effort. It’s a high-amperage electric motor and, once the ignition is disengaged, the starter stops rotating and retracts until the next time it’s needed.
- Electrical wiring. All electrical components require power and/or communication, and electrical wiring is routed throughout the vehicle to connect the systems together. The wires are joined with connectors when they need to be able to disconnect for service, and the thickness or gauge of the wiring varies depending on how much current the system requires. For example, battery cables and starter motor cables are much thicker than wires that carry speed sensor signals.
- Fuses. To protect electrical circuits, a vehicle is equipped with one or several fuse panels. Fuses are inline circuit breakers that burn out when a circuit is drawing more current than it can safely handle.
- Relays. These devices are normally found in fuse panels as well, and they act as an electrically operated switch that allows current to flow in a specified direction when it’s activated. They’re commonly used for controlling power windows, headlights, and other high-power circuits that a normal switch alone can’t handle. Relays can take a small electrical input to switch a high-powered circuit safely and reliably.
How the Electrical System Works?
The car electrical system operates on a 12-volt circuit, with power flowing from the battery, which provides approximately 12.6 volts at rest and is recharged by the alternator to a maximum voltage of 14.8 volts while the engine is running.
As you start the engine, the battery supplies electrical energy to the starter motor, which engages the flywheel and initiates engine motion.
Electricity flows through the car’s metal body to return to the battery, similar to how blood circulates through veins in the human circulatory system.
Once running, the alternator generates high-amperage current to recharge the battery and power electrical components.
Electrical current flows through various components via a wiring loom, protected by fuses that break the circuit in case of excessive current. This guarantees safe operation and energy efficiency in vehicle electrical systems.
Your car’s electrical system relies on these components to function seamlessly.
Current, voltage and resistance
The extent to which a wire resists the flow of current is called resistance, and is measured in ohms.
Thin wires conduct less easily than thick ones, because there is less room for the electrons to travel through.
The energy needed to push current through a resistance is transformed into heat. This can be useful, for example in the very thin filament of a light bulb, which glows white hot.
However, a component with a high current consumption must not be connected using wires which are too thin, or the wires will overheat, blow a fuse, or burn out.
All the electrical units of measurement are interrelated: a pressure of 1 volt causes a current of 1 amp to flow through a resistance of 1 ohm. Volts divided by ohms equal amps. For example, a light bulb with a resistance of 3 ohms, in a 12-volt system, consumes 4 amps.
This means it must be connected using wires thick enough to carry 4 amps comfortably.
Often the power consumption of a component will be stated in watts, which are found by multiplying amps and volts. The lamp in the example consumes 48 watts.
Positive and negative polarity
Electricity flows from a battery in one direction only, and some components work only if the flow through them is in the correct direction.
This acceptance of a one-way flow is called polarity. On most cars the negative () battery terminal is earthed and the positive (+) one feeds the electrical system.
This is called a negative earth system, and when buying an electrical accessory a radio, for example check that it is of a type suitable for your car’s system. Fitting a radio with the incorrect polarity will damage the set, but most car radios have an external switch for setting the polarity to suit that of the car. Switch to the correct setting before fitting.
Short circuits and fuses
If the wrong-sized wire is used, or if a wire becomes broken or disconnected, this can cause an accidental short circuit which bypasses the resistance of the component. The current in the wire may become dangerously high and melt the wire or cause a fire.
To guard against this, ancillary circuits have fuses.
The most common type of fuse is a short length of thin wire enclosed in a heatproof casing often glass.
The size of the fuse wire is the thinnest that can carry the normal current of the circuit without overheating, and it is rated in amps.
The sudden surge of high current in a short circuit makes the fuse wire melt, or ‘blow’, breaking the circuit.
When this happens, see if there is a short circuit or a disconnection, then install a new fuse of the correct amperage rating (See Checking and replacing fuses).
There are many fuses, each protecting a small group of components, so that one blown fuse does not shut down the whole system. Many of the fuses are grouped together in a fuse box, but there may also be line fuses in the wiring.
Series and parallel circuits
A circuit usually includes more than one component, such as bulbs in the lighting circuits. It matters whether they are connected in series one after the other or in parallel side by side.
A headlamp bulb, for example, is designed to have a degree of resistance so that it consumes a certain current to glow normally.
But there are at least two headlamps in the circuit. If they were connected in series, electric current would have to go through one headlamp to get to the other.
The current would encounter the resistance twice, and the double resistance would halve the current, so that the bulbs would glow only feebly.
Connecting the bulbs in parallel means that electricity goes through each bulb only once.
Some components must be connected in series. For example, the sender in the fuel tank varies its resistance according to the amount of fuel in the tank, and ‘sends’ a small electrical current to the fuel gauge.
The two components are connected in series so that the varying resistance in the sender will affect the position of the needle on the gauge.
Ancillary circuits
The starter motor has its own heavy cable, direct from the battery. The ignition circuit furnishes the high-tension impulses to the sparkplugs; and the charging system includes the generator, which recharges the battery. All the other circuits are called ancillary (subsidiary) circuits.
Most are wired through the ignition switch, so that they work only when the ignition is switched on.
This prevents you accidentally leaving something switched on which might cause the battery to go flat.
The side and tail lights, however, which you may need to leave on when the car is parked, are always wired independently of the ignition switch.
When fitting extra accessories, such as a rear window heater which consumes a heavy current, always wire it through the ignition switch.
Some ancillary components can be operated without the ignition turned on by turning the switch to the ‘auxiliary’ position. A radio is usually wired through this switch, so that it can be played with the engine off.
Wires and printed circuits
Wire and cable sizes are classified by the maximum amperage that they can carry safely.
A complex network of wires runs through the car. To avoid confusion, each wire is color coded (but only within the car: there is no national or international system of color-coding).
Most car handbooks and service manuals include a wiring diagram which can be difficult to follow.
The color-coding, however, is a useful guide to tracing wiring.
Where wires run side-by-side they are bound together in a bundle, in a plastic or fabric sheath, to keep them tidy and less difficult to fit.
This bundle of wires stretches over the length of the car, with single wires or small groups of wires emerging where necessary, and is called the wiring loom.
Modern cars often need room for many wires in confined spaces. Some manufacturers now use printed circuits instead of bundles of wires, particularly at the rear of the instrument panel.
Printed circuits are plastic sheets on which copper tracks have been ‘printed’. Components are plugged directly into the tracks.
Conclusion
Vehicle electrical systems comprise many components that include generators to electric wire harnesses connectors and many more.
In this article, we’ve seen the definition, functions, applications, components, and working of a car’s electrical system. I hope you enjoyed the reading, if so, kindly comment on your fav section of this post. And please don’t forget to share. Thanks!