Category Archive: Automotive Electrical Systems

Basics Of Automotive Electrical System – Technosoft

A vehicle is ignited and started by an electrical system. The automotive electrical system is analogous to our body’s circulatory system, where the battery is the heart from which the electricity (blood) flows. Like blood, electrical current flows from the battery to the powered part and back through the car’s metal body.

The battery serves as the electrical system‘s backbone. It gives the car the electricity it needs to start and powers other parts, like the fuel and ignition systems, which are needed for the engine to work.

Hence, this blog is to elaborate on the automotive electrical system, its components, and its functioning.

Basics Of Automotive Electrical System - Technosoft

Main components of an automotive electrical system

There are three main components of an electrical system.

  1. Battery

Your vehicle’s entire electrical current is supplied by its battery until it is started. This includes the current to the ignition and fuel systems, which are responsible for producing the combustion necessary for your engine to operate.

  1. Starter

While the battery provides the power to start a vehicle, it is the starter that actually starts the engine. The battery supplies the starter motor with a small amount of power. The starter then rotates the flywheel, which rotates the crankshaft and initiates piston movement. Due to the complexity of this procedure, it is essential that the starter work.

  1. Alternator

The alternator keeps the battery charged and the electrical system operational while the engine is running. With a faulty alternator, your vehicle may start, but it will not be able to run for an extended period of time. If the alternator needs replacement, the electrical system of your vehicle will operate erratically, the battery will deplete, and the engine will eventually lose power.

How does the current flow within a vehicle?

Current flows out of the battery via its positive terminal and back in via its negative terminal, also known as its “earth terminal,” because it is connected to the car’s chassis and therefore cannot electrocute you. This configuration is known as an earth-return system.

Electricity flows along wires of various hues (and resistance) that are bundled and run the length of the vehicle. This is known as a writing loom.

It is extremely complex and has wires running off it at intervals to connect to power-requiring components.

Types of Batteries

Starting batteries: These batteries start your car. They deliver a short, powerful burst of energy to start the engine. They stay charged during regular use because the alternator recharges them when it starts charging the electrical system.

Deep-cycle batteries: These batteries provide less energy over time. While they can start a car, they are designed to run fridges, winches, and other electrical components that draw a smaller but regular current. Within these categories, lead-acid batteries differ in their materials.

Wet Cell  This is the most common type of car battery and may be maintenance-free or require periodic watering.

Absorbed Glass Mat: Like wet cell batteries, but with a glass mat between each lead plate. This electrolyte-soaked mat reduces battery slosh. It lasts longer than a wet-cell battery.

Gel Cell: As the name suggests, this battery uses a gel electrolyte. They’re smaller than wet-cell batteries.

The working principle in automotive electrical systems

Car electrical systems are easy to understand. All electrical devices in a car are powered by the battery through switches or relays. The engine immediately starts the battery-powered starter motor. The alternator charges the battery while the engine burns fuel. 

When the engine is off, this alternator’s voltage is lower than the battery’s. The battery, not the alternator, powers the vehicle’s loads. Diodes prevent current from entering alternators.

The alternator’s current output exceeds the battery voltage when the engine is running. The alternator charges the vehicle’s battery and electrical load. When the engine is running, an alternator’s output voltage is above the battery voltage.

Wrapping Up

The electrical system is a complex but essential component of your vehicle’s ability to start, run, charge, and perform small but essential tasks such as locking the doors. Moreover, despite the fact that the voltage in automotive systems is significantly lower than in, say, household applications, it is essential to seek the assistance of a professional when making a diagnosis or beginning repairs, as many components are extremely sensitive and can be easily damaged without the proper training and knowledge.

Want solutions for your automotive electric system? Want to power your vehicle design with cutting-edge engineering? Technosoft Engineering is here to provide multi-disciplinary services including styling and body design, electrical part design, engineering documentation, FEA, CFD, VA/VE, functional testing, and much more.

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About Automotive Electrical Systems & Automotive Electrical Engineering

The automotive electrical systems and automotive electrical engineering industry have hyped the popularity of electric and hybrid vehicles. The advancements in vehicular technology with safety features, infotainment, body electronics, and powertrain have flooded the sector with increased demand. With respect to the same demand, the expected market size of automotive electronics is valued at $8.12 billion by 2028, with a CAGR of 7.48% every year.

From classic electronics to passive safety features, automotive electrical Engineering comprises it all. All these features draw their power from a battery. It is a loop where the current flows from the positive terminal of the battery to generate an output like the lighting of gauges and flows back to the negative terminal.

Thus, to get a basic understanding, this article will briefly explain how Automotive Electrical Engineering and automotive electrical systems work.

Automotive Electrical Systems



What is an automotive electrical system & automotive electrical engineering?

The automotive electrical systems & automotive electrical engineering include engine management, ignition, radio, telematics, car puters, infotainment systems, and many more. This system primarily generates, stores, and supplies electricity to vehicle systems. It also controls vehicle electrics like electrical gauges, digital gadgets, power windows, central locking mechanisms, etc.

Components of an automotive electrical system

  1. Magneto

Also known as ignition magneto, is a magneto (electrical generator that uses permanent magnets to produce alternating current) that provides current for the ignition system for a spark-ignition engine, like, a petrol engine. It consists of 3 components-

  1. Permanent magnets
  2. Coil
  3. Cranking mechanism

This converts mechanical energy into electrical energy. With a constant magnetic field strength, it generates a steady output regardless of load variations.

  1. Generator/Dynamo

It supplies the electrical energy for charging the battery that gets the drive from the engine through the fan belt. The generator converts mechanical energy into electrical energy, i.e., direct current (DC). This is because the electric components need DC to function, which they can directly consume. It consists of 3 components-

  1. Frame
  2. Armature
  3. Field coils

A Dynamo takes the help of a commutator and uses rotating coils and a magnetic field to convert mechanical rotation into an electrical supply. They are placed on the tires of electric cars to produce energy and to maintain the efficiency of the car even when the accelerator is not pressed.

  1. Alternator

Also known as AC generator. It is an inevitable part of a vehicle’s charging system. The alternator provides the electrical power that charges the battery, however, the current produced is alternating current (AC). Because vehicles use a 12-volt DC electrical system, this alternating current (AC) power is quickly converted to direct current (DC).

It consists of 4 components-

  1. Frame or housing
  2. Rotor with electromagnets
  3. Stator
  4. Slip rings and bushes

Its efficiency is not limited to fan cooling loss, bearing loss, iron loss, copper loss, and the voltage drop in the diode bridges, but also extends when combined with permanent magnets.

  1. Cut-out relay

Also known as a circuit breaker, regulates and cuts the current output going to the battery. When the engine is running at low speeds, the generator output is frequently lower than the 12-volt battery output voltage. As a result, it is insufficient for charging the battery. 

Because the battery voltage is greater than the generator output, in this case, the battery begins to drain into the generator. A voltage regulator/Cut-Out is used to prevent the battery from draining. It is responsible for connecting and disconnecting the generator from the battery.

The DC generator is connected to a battery through a cut-out relay and an ammeter. It also maintains the voltage between 13.5 and 14.5 volts to protect other electric parts in the vehicle.

  1. Battery

The battery stores electrical energy in DC form for future use. The positive terminal is directly connected to the engine starter motor. It aids in starting the engine by cranking the starter. The alternator immediately charges the battery while the engine is running. When the engine is turned off, the battery can power the electrical components.

Working principle of an automotive electrical system

  1. The Automotive electrical systems in a vehicle are designed with switches or relay systems and are connected to the battery.
  2. When the engine starts, the electrical motor receives power from the battery.
  3. Via the combustion process, the engine keeps running and the alternator keeps charging the battery.
  4. When the engine slows down, the cut-off cuts the power between the battery and the generator.
  5. The alternate output voltage is maintained above the battery voltage to prevent it from draining and ensure smooth operation.

Summing Up

automotive electrical engineering work on the simple principle of electromagnetic induction. They are responsible for advanced automotive features like ABS, ASR, PA, airbags, emergency brakes, driver assistance, navigation systems, and passenger comfort systems. This requires the immense assistance of tools, both hardware and software.

Technosoft is an automotive electrical engineering services provider company. We offer an extensive portfolio of product solutions, including 

  1. Designing and developing individual electrical components
  2. Chassis Electronics and Power Distribution
  3. 2D and 3D Wiring Harness Routing
  4. Wiring Harness Design
  5. Climate Control and Body Electronics
  6. Electrical Components Selection
  7. Electrical & Electronics Schematic System Design
  8. Manufacturing Process Setup
  9. Value Analysis/Value Engineering

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