Fabrication of dc–dc converter using nanocrystalline Mn–Zn ferrites

Abstract

The microwave–hydrothermal method has been successfully used for synthesis of nanocrystalline Mn–Zn ferrites which are used for high frequency applications. The nanopowders were characterised using X-ray diffraction and TEM. The nanopowders were annealed using microwaves at 600°C/10 min. The frequency dependence of dielectric constant ϵ′ was measured in the range from 10 Hz to 1·3 GHz, and initial permeability μi was measured in the range from 10 Hz to 1 MHz. The total power loss was measured at 100 kHz and 200 mT on the annealed samples. Conductor embedded ferrite transformers were fabricated, and output power Po, efficiency η and temperature increase ΔT were measured at sinusoidal voltage of 25 V with frequency 1 MHz. The transformer efficiency η was found to be high, and surface rise of temperature ΔT is very low.