The Use Of Transistors in Automotive Technology You Should Know

Image of transistors source Freepik

Modern automotive is highly characterized by the electronics. We have to admit that development in electronics has changed many industries, automotive is not exception. Take a look at any modern car and you will be impressed by the power of the electronic engineering.

Transistors are among the top electronic components that run the automotive industry. These are semiconductors that are used for a wide range of functions. Among the top functions of transistors include amplifying electrical signals, acting as circuit switches and controlling the flow of electric current.

With the advancement of automotive technology, vehicle manufacturers saw it wise to integrated transistors into different components of a vehicle.

Usually, transistors are carefully integrated into vehicle electrical systems where they perform different functions.

Table of Contents

Overview of transistors

As we have defined, a transistor is a miniature semiconductor device that is designed to control and regulate the flow of current and voltage in a circuit. In most automotive applications, it is referred to as the voltage regulator.

The ability to regulate power is the reason why transistors are always considered to be vital electronic components in automotive industry. They work by controlling the flow of both the electrons and the holes.

There are two main types of transistors used in automotive. These are negative-positive-negative (N-P-N) and positive-negative-positive (PNP). Moth types are relevant in the electronic applications although NPN is the most preferred transistor type since majority of its charge carriers are the electrons.

Both the NPN and the PNP configurations allows the transistor to function as a switch and as well as amplifier.

Parts and components of a transistor

To know the relevance of transistors in vehicles, it will be prudent to know the key parts that make up this semiconductor device.

A typical transistor comprises of three components. These are the base, the emitter and the collector. The three represent the terminals onto which you will connect to the electric circuit.

In most cases, the base is positioned at the center of the transistor and its function is to activate the transistor. It is lightly doped.

On the other hand, the emitter serves as the negative terminal of the transistor. It is heavily doped.

The collector is also a negative terminal ans is positioned on the side of the transistor. It is lightly doped and slightly larger than the emitter.

How does a transistor work?

Since you know the configuration and parts of the transistor, it will be easy to understand the working mechanism.

Regardless of the configuration, there will always be a PN junction on any transistor. The first p-n junction will be between the base and the emitter while the second p-n junction will be between the base and the collector.

The relevance of the three terminals come to play when connecting the transistors to electric circuits.

The idea behind the transistor operation is to allow you to control the flow of current through the junctions and the terminals. This is what we call biasing a transistor.

Let’s take an example of the Bipolar Junction Transistor (BJT) when forward-biased, current will flow through the base-emitter junction. In reverse-bias mode, current will flow through the base-collector junction.

Functions of transistors in automotive

Image source Freepik

Now that you know what transistors are and how they work, let’s look at some of the key roles that they play when used in vehicles.

Transistors in the engine

Engine of modern vehicles feature some electronics. The most notable one is the Engine control unit (ECU).

The ECU monitors, controls and regulates every aspect of a vehicle’s engine.

For example, you the ‘oil-check’ warning light on your dashboard is a message from the ECU that you need to do an oil change.

This is just among the many other engine parameters such as timing, temperature among others.

At the core of the ECU operation are the transistors.

Take an example of the amplification role of the transistors, they amplify the signals from the engine into relevant data.

The act of fuel injection in modern engines is also electrically executed. This is another area where transistors play a critical role.

Engines have many sensors. It is the work of the transistors to regulate to regulate the flow of current to these sensors.

All these functions culminate into a smooth-running engine.

They also allow the driver to monitor the state of the vehicle’s engine at any given time and take necessary actions.

Transistor at a vehicle’s ignition system

A car’s ignition system is is heavily characterized by the electronic components. Transistors are among the key components that play important roles in starting up the vehicle.

The most critical role is when transistors act as switches for the modern vehicles. The rapid-switching capability of the transistors allows the ignition system to generate high voltage that will ignite a car’s engine.

Also, transistors ensure that the switching and amplification of current are done accurately. This in turn facilitates proper timing of the ignition.

Automotive brakes

The braking system of modern cars is electrically controlled and managed. Transistors heavily feature in a car’s brake system. This is mainly due to the fact that there are many brake sensors in most vehicles.

A simple example is the brake warning light that illuminates on your car’s dashboard. The illumination could be because of the worn-out brake pads. Transistors will amplify the signals from the brake pad sensor to the ECU and the dashboard.

The most common application of transistors in relation to the brake system is in anti-lock braking systems (ABS). As the name suggests the main function of this system is to prevent the brake from locking up. This eventually ensures that the car remains steady whenever you are braking.

Where does a transistor come in in the working of an ABS system? The ABS has sensors which monitor and balance the driving behavior and the brake system. These sensors generate signals which are transmitted to the transmitter for switching and amplification. The signals through the transistors will regulate the pressure on the brake system.

In some vehicles, the ABS can be switched On and Off and this is also because of the rapid-switching feature of the transistors.

Control the lights, doors and windows

The role of automotive transistors is even on the most basic functions of the vehicle.

Most modern vehicles have remote-controlled doors that allow you to open by simply pressing the button.

Inside the vehicle, there is a control panel that allows you to open or lock windows. You can also adjust the positions of the mirrors electronically.

Transistors also heavily feature in the lighting systems of vehicles.

In all these applications, transistors mainly play the switching role.

Entertainment system in vehicles

Perhaps this is the most obvious application of transistors in automotive world.

A glance at your car’s entertainment system you will see an amplifier. It boosts or amplifies the audio signal hence the main reason for the high-quality output from the audio system.

Amplifiers are also essential for the vehicle’s visual entertainment system.

What about the switches? They are primary components on a car’s entertainment system.

You should also remember a vehicle’s radio relies on the transistors for the better output signals.

Driver assistance systems

Most modern vehicles have driver assistance systems (DAS) which are electronically powered. These assistance systems include rear-view cameras, blind-spot monitor sensor, lane assistance, cruise control system, parking assistance system among others.

LIDAR mapping technology and even AI are some of the technologies that run these ADAs. Transistors tend to be at the background of these technologies. They either serve as switches, voltage regulators and amplifiers for most driver assistance systems.

Market trends for the transistors in automotive

Knowing the roles of transistors in the automotive world is not enough. You should also know the market trends that are having major effects in the industry. This is vital especially if you want to buy automotive transistors in bulk.

A reputable transistor market report predicted a growth of the transistor market at a CAGR of 4.1%. This growth is estimated to take place at a period of between 2020-2027.

The rising demand for transistors in different devices is among the key reasons for such upwards projection. The automotive industry is among the top segments that heavily rely on the transistors.

Consumers are always yearning for new technologies in vehicles. In fact, car manufacturers are striving to outdo each other on the electronic features that they add on the vehicles. This is among the key drivers for the growing demand of transistors in vehicles.

What about the evolution of electric vehicles? This is another automotive segment that is poised to increase the demand for the transistors.

The fact that everything about these vehicles fully depend on electricity means that the presence of transistors will be felt in every aspect of the car.

Also, since EVs are defining the future of automotive, the demand for the transistors will be on an extremely new high levels.

Are you working on an automotive project, now you can easily appreciate the critical roles of transistors in automotive technology.