Bidirectional temperature-sensitive magnetic semiconductor and its application

Certain ferrites, referred to as temperature-sensitive magnetic semiconductors (TMS), exhibit marked temperature dependence in both magnetic and electrical fields. The temperature dependence of TMS resistance is similar to a semiconductor thermistor at low voltages. At higher voltages, three states are observed in the symmetric bidirectional characteristics: a cut-off state; a negative resistance state; and an ´on´ state. Therefore a TMS can be regarded as a multifunction magnetic semiconductor, which has the effect of adding a thermistor and a bidirectional switching device to the temperature-sensitive magnetic core. Application of a TMS switching device for overheating and overvoltage protectors is also discussed.<>