PC-based apparatus for characterising high frequency magnetic cores

A PC-based automatic characterisation system (ACS) has been developed to automatically characterise magnetic materials under square wave cyclic excitation from 1 kHz to 100 kHz. A computer-controlled AC to AC converter has been developed for the excitation circuit. A digital oscilloscope gathers the required data through the 8255 interface card. The errors in the ACS have been analysed and overall repeatability is better than ±0.35%. The system has the advantages of ease of use, absence of long-term measuring system drifts and ready variation of high induction and high frequency test parameters. The system operates automatically and measurements on three commercial core materials are reported. Comparisons with the data of manufacturers are included