BH hysteresis measurement system for thin soft magnetic materials

In this work, a computer controlled automated system is designed for the evaluation of magnetic properties of thin soft magnetic materials. Magnetic measurements were conducted using a National Instrument Data Acquisition card, a signal generator, a power amplifier circuit for the signal voltage, and an AD620 voltage amplifier circuit for the induced voltage in the secondary coil. The LabVIEW software was used for controlling the hardware and processing the experimental data points to draft a BH-hysteresis loop for the sample. A dedicated feedback loop algorithm was designed for controlling the waveform of the flux density at the secondary coil during the magnetization process. Based on the results obtained, it is shown that the accuracy of coercivity measurement is increased using the sinusoidal flux density. The high accuracy instrumentation amplifier circuit together with the flux density control feedback loop made it possible to examine the magnetic properties of thin samples.

Automated summary

A computer controlled automated system was designed to evaluate magnetic properties of thin soft magnetic materials, utilizing magnetic measurements and LabVIEW software. The accuracy of coercivity measurement was increased by using sinusoidal flux density, with a high accuracy instrumentation amplifier circuit and flux density control feedback loop for examining magnetic properties of thin samples.