Murata Manufacturing Co., Ltd.

Hideaki Tsukada

Yukinori Ueda

Katsuhiro Onishi

Fumitoshi Masuda

Kiminori Yamauchi

Yoshiyuki Nakatsu

Miroyuki Kishishita

A first rotor and a second rotor are prepared. The first rotor has a resistor and inner-peripheral and outer-peripheral electrodes respectively connected to end portions of this resistor. The second rotor has a resistor and inner-peripheral and outer-peripheral electrodes symmetrical with those of the first rotor, provided at a position corresponding to that obtained by rotating the first rotor about the axis of the first rotor by an angle of 180&deg; with respect to the first rotor. A variable resistor selectively uses either one of the first rotor and second rotor. This makes it possible to provide a variable resistor which requires few parts. Also, this makes it possible to reduce the kinds of bending operations that must be performed on the terminals.

Variable resistor

A variable resistor comprises a case, slide contactors, a rotor, a metal cover and lead terminals. Arms which are respectively provided at central portions of the slide contactors protrude from a bottom surface of a recess portion of the case and are each shaped like a comb. The arms are respectively contacted, at contact portions A, B and C, by electrodes and resistor of the rotor. Lead terminals are each circular in cross section and are respectively connected, at end surfaces of their lead wires, to the slide contactors. This makes it possible to obtain a variable resistor which is easy to manufacture, low in cost and excellent in reliability.

A first rotor and a second rotor are prepared. The first rotor has a resistor and inner-peripheral and outer-peripheral electrodes respectively connected to end portions of this resistor. The second rotor has a resistor and inner-peripheral and outer-peripheral electrodes symmetrical with those of the first rotor, provided at a position corresponding to that obtained by rotating the first rotor about the axis of the first rotor by an angle of 180.degree. with respect to the first rotor. A variable resistor selectively uses either one of the first rotor and second rotor. This makes it possible to provide a variable resistor which requires few parts. Also, this makes it possible to reduce the kinds of bending operations that must be performed on the terminals.

There is provided a variable resistor having a small number of parts and having an excellent heat releasing property. A rotor is rotatably contained in a concave portion of a case. The rotor has a resistive element provided on the bottom thereof and electrodes connected to both ends of the resistive element. Arms of sliders are provided on the bottom of the concave portion of the case in a sliding relationship with the respective electrodes and resistive element. A metal cover is disposed on the upper surface of the case in contact with the rotor.

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Sabae, Japan

Hideaki Tsukada