Major B-H Loop Measurement of Toroidal Shape Magnetic Powder Core

Dept. of Photonics and Sensors, Hannam University, Hannamro 70, Daedeok-gu Daejeon 306-791, Korea(Received 9 June 2014, Received in final form 18 June 2014, Accepted 19 June 2014)Toroidal cores made of metallic powder requires large magnetic field strength up to few decade kA/m to obtain major hysteresisloop. To overcome thermal heat generation problem from large exciting current during measurement, we have employed a real timehysteresis loop tracer which can digitize and calculate B-H signals in personal computer as real time. For example, when wemagnetize specimen at 10 Hz frequency, we could display hysteresis loops 10 times per second. Using the real time hysteresis looptracer, we could measure major hysteresis loop of toroidal shape metallic powder core at maximum flux density or maximummagnetic field strength to be measured within 5 second not to significant increasement of specimen temperature due to the heatdissipation from coil windings. For the constructed hysteresis loop tracer, we could measure hysteresis loop at magnetic field strengthhigher than 50 kA/m for the toroidal shape specimen.Keywords: magnetic measurement, toroidal core, magnetic powder core, B-H loop tracer, major hysteresis loop