Higher Frequency Magnetic Single Sheet Tester
Vaclav Havlicek, Martin Pokorny
DOI:
Abstract
Testing of magnetic properties of amorphous and nanocrystaline materials at AC magnetization represents very complicated problem of open specimen homogeneous magnetizing with the exactly defined magnetic flux waveform, the precise conversion of magnetic variables to the electrical ones and the measurement of integral values of strongly distorted electrical variables. Difficulties of these measurements are increasing with increasing frequency. The new Single Sheet Tester (SST) for open specimen magnetic measurement up to frequency 20 kHz has been developed at CTU in Prague, Dept. of circuit Theory. The new SST consists from the yoke with MMF compensation, and the power amplifier for excitation up to magnitude 100 V and currents up to 3 A at frequencies from 1 kHz to 20 kHz. The control and measuring system is completely digitalized and the core of it is based on PC plug-in cards. The paper presents the basic ideas of SST design and the first practical experience with the realized SST prototype.