Murata Manufacturing Co., Ltd.

Hiroki Tanaka

Toshiharu Hirota

Yutaka Ikeda

Takeo Haga

Yoshinori Kitamura

Hiroshi Kuwahara

A positive temperature coefficient thermistor device includes a laminate of a lower insulating plate, a positive temperature coefficient thermistor element, and terminal assemblies. The laminate is disposed in a hollow portion in a metal body. The device also includes a pressure spring made of a metal plate that is bent such that the cross-sectional shape thereof in a plane substantially orthogonal to the longitudinal direction thereof is substantially constant. The pressure spring is disposed between the top surface of the hollow portion and the terminal assembly adjacent to the top surface of the hollow portion such that the pressure spring and the laminate are resiliently supported inside the hollow portion. With this structure, the pressure spring can be easily inserted without damaging electrodes of the positive temperature coefficient thermistor element, and an insulator can be easily arranged without damaging the insulator.

Positive temperature coefficient thermistor device

A surface-mount positive temperature coefficient thermistor includes a disk-shaped positive temperature coefficient thermistor element having electrodes provided on opposing main surfaces thereof, an insulating case having an inner space with the thermistor element inserted therein, and a pair of metal terminals arranged to make electrical contact with the respective main surface electrodes of the thermistor element, and to sandwich therebetween the thermistor element. The insulating case includes a pair of main surfaces that are substantially parallel to the main surfaces of the thermistor element, a pair of opening side surfaces each having an opening, and a pair of end surfaces each having a terminal insertion hole provided therein. One end of each of the pair of metal terminals is inserted from the respective terminal insertion holes into the inner space, and the metal terminals press-hold the thermistor element so as to sandwich the thermistor element therebetween.

Surface-mount positive temperature coefficient thermistor and manufacturing method therefor

A starting circuit for a single-phase induction motor includes a motor starting positive characteristic thermistor and a triac arranged in a series connection, and a triac control positive characteristic thermistor connected in parallel with the motor starting positive characteristic thermistor, and including one terminal thereof connected to a gate of the triac. The triac control positive characteristic thermistor has a volume in the range of about 4.5 mmto about 30 mm. The relationship of (&#x221a;2&#xd7;V&#xd7;sin 45&#xb0;)/R&#x2267;I is maintained with the triac control positive characteristic thermistor within an operating temperature range, where V represents a root-mean-square value of a power source voltage, R represents a resistance of the triac control positive characteristic thermistor, and I represents a gate turn-on current of the triac. The gate turn-on current I at an operating temperature of about 25&#xb0; C. is about 20 mA or less.

Starting circuit for single-phase induction motor

An inexpensive positive temperature coefficient thermistor has metal terminals which have been miniaturized without deteriorating the characteristics or sacrificing the reliability of the device. The metal terminals include supporting members and springs constructed such that a total width of the supporting members is smaller than a total width of the springs. In addition, connecting portions at the upper ends of the metal terminals engage with a case main body or a covering member to be retained at predetermined positions.

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Higashiomi, Japan

Hiroki Tanaka