Abstract: A thermistor with positive resistance-to-temperature characteristic used in a overcurrent protection circuit has electrodes on mutually opposite main surfaces and is mounted to a substrate having electrically conductive members such that deterioration of its voltage resistance due to heat emission can be controlled. A spacer with smaller thermal conductivity than the substrate and penetrated by a conductor piece with a small cross-sectional area is inserted between solder materials connecting to one of the thermistor electrodes. The other electrode is contacted by an elongated connecting member through its sectional surface transverse to its longitudinal direction such that the cross-sectional area of electrical conduction is reduced.

Abstract: A thermistor with positive resistance-to-temperature characteristic used in a overcurrent protection circuit has electrodes on mutually opposite main surfaces and is mounted to a substrate having electrically conductive members such that deterioration of its voltage resistance due to heat emission can be controlled. A spacer with smaller thermal conductivity than the substrate and penetrated by a conductor piece with a small cross-sectional area is inserted between solder materials connecting to one of the thermistor electrodes. The other electrode is contacted by an elongated connecting member through its sectional surface transverse to its longitudinal direction such that the cross-sectional area of electrical conduction is reduced.

Abstract: A thermistor with positive resistance-to-temperature characteristic used in a overcurrent protection circuit has electrodes on mutually opposite main surfaces and is mounted to a substrate having electrically conductive members such that deterioration of its voltage resistance due to heat emission can be controlled. A spacer with smaller thermal conductivity than the substrate and penetrated by a conductor piece with a small cross-sectional area is inserted between solder materials connecting to one of the thermistor electrodes. The other electrode is contacted by an elongated connecting member through its sectional surface transverse to its longitudinal direction such that the cross-sectional area of electrical conduction is reduced.

Abstract: A thermistor with positive resistance-to-temperature characteristic used in a overcurrent protection circuit has electrodes on mutually opposite main surfaces and is mounted to a substrate having electrically conductive members such that deterioration of its voltage resistance due to heat emission can be controlled. A spacer with smaller thermal conductivity than the substrate and penetrated by a conductor piece with a small cross-sectional area is inserted between solder materials connecting to one of the thermistor electrodes. The other electrode is contacted by an elongated connecting member through its sectional surface transverse to its longitudinal direction such that the cross-sectional area of electrical conduction is reduced.

Abstract: A thermistor with positive resistance-to-temperature characteristic used in a overcurrent protection circuit has electrodes on mutually opposite main surfaces and is mounted to a substrate having electrically conductive members such that deterioration of its voltage resistance due to heat emission can be controlled. A spacer with smaller thermal conductivity than the substrate and penetrated by a conductor piece with a small cross-sectional area is inserted between solder materials connecting to one of the thermistor electrodes. The other electrode is contacted by an elongated connecting member through its sectional surface transverse to its longitudinal direction such that the cross-sectional area of electrical conduction is reduced.

Abstract: A thermistor with positive resistance-to-temperature characteristic used in a overcurrent protection circuit has electrodes on mutually opposite main surfaces and is mounted to a substrate having electrically conductive members such that deterioration of its voltage resistance due to heat emission can be controlled. A spacer with smaller thermal conductivity than the substrate and penetrated by a conductor piece with a small cross-sectional area is inserted between solder materials connecting to one of the thermistor electrodes. The other electrode is contacted by an elongated connecting member through its sectional surface transverse to its longitudinal direction such that the cross-sectional area of electrical conduction is reduced.

Abstract: A small-size high-performance electronic protective device (10) is provided for use in protecting communication equipment including an exchange servicing module against application of abnormal surge current due to accidental shorts between adjacent ones of power feed lines in a communications system. The protective device (10) includes positive thermistors (3a, 3b) connected between communication link input terminals (1a, 1b) and output terminals (1c, 1d) coupled to an associative equipment being protected. The protective device (10) also includes thick-film resistive elements (5a, 5b), which are connected in parallel with the thermistors (3a, 3b), respectively.