A multiple-output 400kHz switching power supply using a new ferrite material H63A

A multiple-output 400kHz switching power supply using a new ferrite material H63A was developed. The power supply, with an efficiency of 74% and an output power of 6.3cc/W, had a single-ended forward type main transformer. The core shape was EE- 30, determined by output power and the winding window area specified in safety standards. The temperature rise of the transformer in operation was examined while changing core materials. The least temperature rise was observed when H63A was used as the core material. H63A was also found to be suitable for high frequency power applications.