A high frequency transformer follows the same fundamental principles as ordinary transformers when it comes to operation. Most notably, high-frequency transformers work at significantly higher frequencies than line voltage transformers. For example, most line voltage transformers run at 50 or 60 Hz, while high-frequency transformers operate between 20 kHz and more than one megahertz (MHz).
Benefits of a High Frequency Transformer
Operating at a higher frequency provides several advantages, the first of which is the size reduction. The smaller the transformer can be for a given power rating, the higher the frequency at which it can operate. Second, because the transformer is smaller, less copper wire is required, which reduces losses and helps to improve the efficiency of the transformer.
Furthermore, because the core is often built of ferrite, many shapes are available, allowing the transformer to be customized to the specific application. No matter if extra shielding or a certain form factor is required, the likelihood is high that a ferrite core can be found that meets the application’s needs.
Challenges of a High Frequency Transformer
The advantages of lightweight, compact size, and better power density outweigh some drawbacks. Minimizing concerns like skin and proximity effects is critical when building a high frequency transformer.
The tendency of high-frequency currents to flow on the surface of conductors causes skin effects. The use of Litz wire can help to decrease losses caused by the skin effect. The magnetic fields from neighboring conductors, either in adjacent windings or, more importantly, in adjacent layers, cause current to flow in undesired patterns or in eddy currents, causing proximity effects, also known as eddy current losses. For more information, please visit Amp-Line Corp.
