Size Reduction of Airborne Transformers

It is important that transformers for airborne applications be as small as possible. The volume and weight of transformers can be reduced by simplifying the design, and by using better application practices and closer mechanical tolerances. The size can also be reduced by increasing the frequency, current density, coil space factor, or flux density in the transformer. Figs. 1 and 2 show how loss and heat density of the transformer are increased as the size is reduced. Greater heat density can be used if the transformer has improved thermal conductivity, or higher temperature insulation. Performance of a sample transformer using built-in thermal conductors demonstrates the advantage of this system of removing heat. Another sample design using silicone insulation shows how high-temperature materials can be used to reduce size. By using these techniques, it is possible to reduce greatly the size of transformers. To get best results, all the factors affecting size should be considered in order to select an optimum arrange- ment.