Abstract: A variable resistor uses a carbon fiber-base resistor with a specific distribution of carbon particle sizes. Because the particle size distribution of carbon fiber is approximately equal to the normal distribution and 80% by volume or more carbon fiber is included in the particle size range from 1 to 20 &mgr;m, high conductivity in the fiber length direction of carbon fiber that is served as structural material for improving the wear resistance does not affect the micro-linearity.

Abstract: A temperature sensor which can be used at ordinary temperatures is provided. After a lamination plate of a phenol resin is carbonized at 640 to 750.degree. C., the powder of the carbonized material and the binder formed of a thermosetting resin, such as phenol or epoxy, are kneaded and formed into a paste, after which this paste is printed between terminals of a base film, such as polyimide, having a high resistance to heat and is calcined at a low temperature. Thus, a temperature sensor such that a resistance element is printed on the base film is obtained. The temperature sensor shows a large change of the resistance value with respect to an environment temperature change at ordinary temperatures.

Abstract: In a variable resistor of the type wherein there is formed on an insulating substrate a resistive member having wide portions and narrow portions in the sliding direction of a slide member and ends thereof wired respectively to a ground terminal and an input terminal. A plurality of contact elements formed on said slide member are brought into sliding contact with said resistive member and a high resistance film allowing the passage of electrostatic charges therethrough is formed at portions of said insulating substrate lying within the sliding passage of said contact elements so that a part of said contact elements comes into contact therewith when it comes off from said resistive member.