Murata Manufacturing Co., Ltd.

Norihiro Mochida

Yoshihiro Yamada

Haruo Takahata

Toshikazu Nakamura

A positive thermistor element is supported by being clamped by first and second resilient contact members that are opposed to each other so as to be disposed along a diagonal and first and second positioning protrusions that are opposed to each other so as to be disposed along the other diagonal of the positive thermistor element. The first resilient contact member is located toward the periphery of the positive thermistor element from the second positioning protrusion and the second resilient contact member is positioned toward an inner portion of the positive thermistor element from the first positioning protrusion.

Electronic device

A positive thermistor device used in a motor activating circuit device of a refrigerator for example includes a positive thermistor element having a pair of opposed electrodes, each of which receives compressive force elastically applied from a corresponding one of spring contact members to hold the thermistor element at a predefined position in the device. When the thermistor device is destroyed, the element breaks into fragments, some of which remain in contact with the spring contact members. The remaining fragments deviate in position to ensure that they do not conduct electricity, resulting in an open state, wherein any current flow is inhibited through such fragments. More specifically, a positive thermistor disk is held within the device so that it is interposed between conductive spring contact pieces and insulative position-alignment projections, which are cross-diagonally situated with respect to each other. The spring contact pieces are located further toward the periphery of the disk than the position-alignment projections, causing a spring force to extend in a direction generally outward relative to a direction perpendicular to the planes of the electrodes. In one embodiment, the position-alignment projections have cut-away portions at outer tip ends thereof respectively to further promote the formation of an open circuit state upon the occurrence of malfunction.

Motor activating circuit device and refrigerator

A positive thermistor device includes a positive thermistor element having a pair of opposed electrodes, each of which receives compressive force elastically applied from a corresponding one of spring contact members to hold the thermistor element at a predefined position in the device. When the thermistor device is destroyed, the element breaks into fragments, some of which remain in contact with the spring contact members. The remaining fragments deviate in position to ensure that they do not conduct electricity, resulting in an open state, wherein any current flow is inhibited through such fragments. More specifically, a positive thermistor disk is held within the device so that it is interposed between conductive spring contact pieces and insulative position-alignment projections, which are cross-diagonally situated with respect to each other. The spring contact pieces are located further toward the periphery of the disk than the position-alignment projections, causing a spring force to extend in a direction generally outward relative to a direction perpendicular to the planes of the electrodes. In one embodiment, the position-alignment projections have cut-away portions at outer tip ends thereof respectively to further promote the formation of an open circuit state upon the occurrence of malfunction.

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Nagaokakyo, Japan

Norihiro Mochida