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What Is Transformer PCB, Its Uses, Working, And Types?

Transformers consider the essential part of a PCB. But each PCB requires a different type of transformer based on their needs and usage. This article focuses on the features of PCB-mounted transformers, which help you identify the best transformer. 

Transformers come in compact and lighter forms and can work under heavy loads. Moreover, one must consider a few important factors before considering any transformer for the device. Therefore, let’s dive into the details of transformers, their types, features, and function.

Overview Of Transformer PCB

Generally, a transformer consists of two coils that are physically separated from each other. These coils are coupled with the electromagnetic field inductively, which occurs between the secondary coil and primary coil. A Printed Circuit Board-Mount transformer acts as a basic component that incorporates the surface of the PCB. This helps in transferring power between two circuits. Another thing to understand here is that the process of transferring power occurs through coils while keeping them completely isolated.

It has an input and an output side. The transformer keeps both sides separated. Separation serves as an essential need in this process.

An actual transformer does not use a simple type of structure in which the square magnetic central part is surrounded with coils and gives magnetic coupling. However, it follows the complex design of the core and coil. This involves core-shell, stacked topologies, and lamination. A designer must take specific considerations while designing the board. Make sure to keep the coils separate and focus on the strength of inductive coupling, as this determines the power transmission efficiency. 

What Are Transformer PCBs?


Transformer acts as an electrical component that helps transform electrical power from one part of the circuit to another circuit part. Transformer offers more benefits and features to the devices. A transformer helps in isolating the device from a power source and disconnecting its connection from the earth. This ultimately protects anyone from touching the open wires accidentally. Moreover, it also helps in converting the current and voltage without impacting the power level. The incorporation of transformers in the power source can help to do so. It also amplifies the wave input. Additionally, it aids in converting the electricity of wires to an appropriate current and voltage for each device. 

Transformers that mount over the surface of circuit boards refer as PCB-mount transformers. They act as vital electrical components. As the majority of PCBs operate on less consumption of power, the addition of transformers helps the PCB to amplify those signals and enhances the electricity power.

How Do Transformer PCBs Work?

Along with the fact that transformers help in transferring electrical power between two circuits. Let’s dive further into details. How can a transformer do that? Generally, a transformer consists of three basic parts, which include both magnetic as well as electronic components. However, these parts include the primary coil, core or central part, and secondary coil.

However, as far as its functionality concerns. Transformers follow three basic steps to work. Firstly, the current passes through the primary coil. Here it induces the flow of a magnetic field inside the metallic core. It then passes through the secondary coil. Here, the magnetic field flow induces the flow of electricity in the second coil. 

Composition of Transformer PCBs

Each PCB transformer consists of two types of coils. Primary and secondary. These coils are made of copper wire which is tightly coiled around the core of the magnetic field. Magnetic core also consists of metal alloys like steel or other material. Moreover, transformers also contain outer casings and terminals. 

However, PCBs follow two different types of mounting techniques to incorporate the transformer over the board surface. These two methods include:

· Surface Mounted

This method uses solder paste and soldering techniques to solder the transformer over the PCB surface directly. However, if the PCB is exposed to harsh environments or greater heat, it may loosen the solder paste.

· Through Hole

This approach needs to drill holes and use leads to pass through those holes. This helps in soldering the transformer using through-holes on each side of the PCB.

Specifications of Transformer PCBs

PCB transformers also have some specifications to look into. These factors include:

· Primary And Secondary Ratings

This rating depicts the rate of current and voltage between the primary coil and the secondary coil. Firstly, check the value of the output voltage. Then look into the current value and compare it with the design value. Moreover, ensure that the density of power increases as this dissipates the heat from the faulty PCB. 

· Power Rating And Efficiency

The power rating indicates the type of current, DC or AC. It also determines the transformer limit for handling power. You must consider the voltage frequency too. Moreover, power efficiency determines the efficiency of DC under little load.

· Form Factor

A transformer can either incorporate vertically or flat over the surface of the board. However vertical transformers may save some space on the board, but they are susceptible to vibrations.

· Mounting Style

Ensure the type of transformer. The SMT-type transformers need soldering techniques to incorporate them over the board. Whereas, THT type transformers need drilling holes and lead to pass through the holes and then solder the transformer over the other side of the PCB. These THT transformers provide greater heat resistance.

· Cooling Mechanism

PCB-mount transformers consume less power. Thus, this creates less heat which automatically obscures the need for any external cooling system. At the same time, the planar PCB transformers can easily hole a heat-dissipating sink over the device.

· Inductance

Inductance generally describes the efficiency of how well a transformer creates a connection between both circuits. However, inductance also belongs to the DC-DC converter PCBs where the power efficiency determines the performance of coupling of a transformer simplicity.

Types Of Transformer PCBs


The PCB transformer comes in various shapes and sizes with different power converters.

· Audio transformers

This transformer helps in converting the signal and sounds from a higher frequency level of 300 Hz to a lower frequency level 20kHz.

· Auto Transformer

Autotransformers contain one winding coil. This solely acts as primary as well as secondary. This enables them to have different types of secondary voltage configurations. One can connect the taps over the transformer using distinct conversion ratios. As it has no separate coils, they do not give isolation

· Balun Transformers

This allows the interface of unbalanced and blanched lines without affecting the arrangement of impedance on either side.

· Current Sense Transformers

These transformers identify and analyze the ampere in a primary coil. Then creates a proportional current in a secondary coil.

· Flyback Transformers

This transformer is also referred to as LOPT or FBT. It generates high voltage signals of saw-toothed at a very high rate of voltage.

· Interface Transformers

These transformers help in communication and telecom circuits to isolate signals.

· Lighting Transformers

These transformers help in generating appropriate power for lumination and lighting systems.

· Medical Transformers

These transformers follow strict rules and regulations for safety. This enables them to be used safely in medical, surgical, and operating devices.

· Power Transformers

These types of transformers help in enhancing the power of the power supply in the device. Manufacturers use these transformers in speakers and amplifiers to amplify the singles and sound.

· RF Transformers

These transformers help in matching impedance, provide isolation of Direct current between the circuits, and provide step-ups and step-downs of voltage and current.

· Resonant Transformers

These types of circuits are used in radios which aid in switching the power supply and bandpass filters.

· Switch Mode Transformers

These transformers function under a low supply of voltage. Thus making them ideal to use in domestic and industrial applications.

Should You Design Your Own Transformer PCBs Or Inductor?

Generally, many designers want to build their own power conversion electrical components. This, however, does not seem impossible to do. Anyone can do so. But it requires complex knowledge. Because of the safety and regulatory measurements on magnetic power, one must look for a PCB transformer manufacturer and design components with them. The best way is to select the best off-the-shelf transformer that suits your needs. Then utilize a regulator over the output value; this gives you the required output voltage.

However, even if you work with a PCB transformer manufacturer, you have to specify a few things first. For example, its material, type of process, and the circuit board. Each manufacturer has their own way of methods that they follow to produce transformers without hurting the safety measures. These measures ensure that you get a perfect, error-free, and safe design without damaging anything.


This article briefly describes the PCB transformers, their types, function, how they work, and factors to consider while choosing them. This also explains the electromagnetic mechanism of transformers. Moreover, the factors help you understand which transformer acts best for your device. It also explains how each type differs from each other. This article gives basic yet important details about PCB transformers, how, where, and when to use them.


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