Matsushita Electric Industrial Co., Ltd.

Kazuo Ishikawa

Hideo Mifune

Yoshio Irie

Kazuo Hosaka

Mamoru Miyamoto

A self heat generation type positive characteristic thermistor and a manufacturing method thereof. The thermistor is made of more than three layers of positive characteristic thermistor element bodies, such that the specific resistance of the layer situated nearer the surface in the direction of element thickness perpendicular to electrodes is higher. According to this invention a positive characteristic thermistor which generates heat instantaneously when a large current is flown therethrough and has excellent thermal shock proof properties can be obtained simply. The thermistor is well suited to mass production and the use of the thermistor can be extended to many fields.

Self heat generation type positive characteristic thermistor and

A sealed thermostatic heater for use in a hair curling iron which uses a positive temperature coefficient (PTC) thermistor as a heat source together with a wire-wound heater, coated heater or ceramic heater.

Sealed thermostatic heater

A constant temperature heater includes a thermistor having a positive temperature coefficient and a varistor stacked upon one another in an electrically insulating casing in such a manner that the thermistor and varistor are electrically connected in series with each other and the thermistor is in heat exchange relationship with a radiator plate on the casing. A spring in the casing presses the varistor and thermistor into firm engagement with each other and biases the thermistor into good heat conductive relation with the radiator plate. The varistor serves to reduce the transient currents in the thermistor and reduces the heat dissipation power of the thermistor, thereby providing a longer service life.

Growing community of inventors

Kadoma, Japan

Kazuo Ishikawa