PCB transformer (Printed Circuit Board Transformer), also called PCB mount transformer, is a kind of compact electrical transformer, soldered or mounted onto the surface of a printed circuit board. It is used to convert voltage and current, and provide providing electrical isolation and impedance matching, and protect the device. Most PCB transformers are considered low-voltage transformers, but they can be designed for high-voltage operation in certain cases.
What Does a Transformer on a Circuit Board Look Like?
What does an electrical transformer look like? Here an image of various types of PCB transformers from custom electrical transformer manufacturer Partopia.
There are many different looks of printed circuit board transformers because they are designed for different purposes, power levels, sizes, and safety requirements. Even though they all do similar jobs, their shape and construction can vary a lot.
What is the Basic Structure of a PCB Transformer?
As shown in the images blow, PCB transformers contains these important parts:
1. Magnetic Core
The magnetic core of PCB transformer provides a path for magnetic flux, usually made from ferrite (for high-frequency) or laminated steel (for low-frequency).
The core shapes include E-core, EE, EI, toroidal, pot core, planar core, etc.
2. Primary Winding
The primary winding is the coil that receives the input energy, usually made of copper wire or copper traces (in planar transformers). The coil is often insulated for safety and to meet isolation standards.
3. Secondary Winding
The secondary winding is the coil that outputs energy after magnetic coupling. It may have multiple taps for different voltages, also insulated from the primary for electrical isolation.
4. Bobbin (Coil Former)
The bobbin is usually a plastic frame that holds the windings, helping maintain spacing and insulation.
5. Insulation System
The insulation system Includes tape layers, enamel coatings, edges, and encapsulation materials.
It functions to keep the safe creepage and clearance distances as required by regulations.
6. Pins or Terminals
The pin connect the windings to the circuit board, and depending on the product design, either through-hole or surface-mount types can be chosen.
7. Encapsulation / Potting (Optional)
When needed, encapsulation or potting with resin or a casing helps protect electronic transformer against mechanical stress, water damage, and electrical risks.
The Working Principle of PCB Transformer
The working principle follows Faraday’s law of electromagnetic induction. When alternating current flows through the primary coil, it generates an alternating magnetic field. The primary core transmits this magnetic flux to the secondary coil. The voltage made by the secondary coil depends on how many turns it has, enabling energy or signal transmission and conversion.
Types of PCB-mounted transformers
- Power transformer
- Pulse transformer
- RF transformer
- Current sensing transformer
- Flyback transformer
- Balun transformer
- Resonant transformer
Application Scenarios of PCB Mount Transformers
PCB mount transformers seem “hide” from our eyes in everyday life, but they’re actually everywhere. Most of PCB transformers are tucked inside a case, because every electronic device’s PCB needs a housing to stay reliable, compliant and long-lasting. Where do we find them? In products you’re already familiar with, like switch-mode power supplies, adapters, chargers, Audio amplifiers, communication modules, LED drivers, industrial controls, automotive electronics, medical devices, etc.
Where to Buy Circuit Board Transformer?
If you intend to customize or purchase printed circuit board transformer in bulk, feel free to contact Partopia. Partopia is a reliable PCB transformers factory in China. With over 30 years of expertise, Partopia is capable of provide your ideal PCB tranformers. Contact Partopia right now!
