Converter Technology

Custom Magnetics Design

In most switched-mode power supplies, magnetic components are required to provide a number of different functions including energy transfer, isolation, energy storage and noise filtering. Some of the magnetic components are standard off-the-shelf parts but normally the main power transformer is a custom designed part.

We wind all prototype transformers in-house to check electrical performance
Prototyping an EF25 High Frequency Transformer

The design process for any custom parts must take into account many parameters:-

  1. Allowable core and winding temperature rise
  2. Safety creepage and clearance from primary to secondary
  3. Winding type and construction to give good coupling and low common-mode noise
  4. Avoiding core saturation
  5. Manufacturability

Design of an efficient power transformer for a given application requires consideration of many different loss mechanisms including winding loss and core loss. In addition, parasitic elements such as leakage inductance and winding capacitance should be minimised through careful choice of winding structure.

As part of our design process, we fully specify and wind any custom magnetics in-house to test before releasing to an external partner for production. This approach minimises the time lag normally associated with specifying and sourcing custom magnetics parts.