Patent ID: 7019613

Claim:
At least twenty arbitrarily selected PTC thermistor bodies produced from a common body of thermistor body material, each of the at least twenty PTC thermistor bodies disposed between a pair of electrodes opposing each other in a PTC thermistor having a positive resistance vs. temperature characteristic; said PTC thermistor bodies including, at least, a thermoplastic resin and an electrically conductive powder that includes an electrically conductive particle made of a metal; said thermoplastic resin and electrically conductive powder having respective contents and a state of dispersion adjusted so as to yield an average magnetization value of 4.0×10 −5 to 6.0×10 −5 Wb·m·kg −1 when a magnetic field of 3.98×10 5 A·m −1 is applied to each PTC thermistor body within the at least twenty PTC thermistor bodies, wherein the average magnetization value is an average value obtained from measurements of the at least twenty PTC thermistor bodies produced from said common body of thermistor body material; said electrically conductive powder including a particle having a specific surface area of 0.8 to 2.5 m 2 ·g −1 and a bulk density of 0.25 to 0.40 g·cm −1 .