| 摘要 |
A potentiometer or variable resistor adapted to be fabricated in subminiature size. The potentiometer or resistor comprises a top assembly and bottom header, and an insulating shell or casing. The top plate assembly is co-molded with a plastic bearing member for the adjustable shaft carrying the contact brush or wiper. The top plate is also co-molded with the insulating brush block on the adjustable shaft. A plastic sleeve is positioned between the brush block and the adjusting shaft to secure the block in place, provide a friction-clutch drive for turning the brush block and contact wiper which will slip if the shaft is turned after the block strikes the stop at the end of its travel, and act as a cushion between the metallic shaft and the molded block when the potentiometer is subjected to relatively large temperature changes. Terminals are provided, in the bottom header, for the contact wiper and resistance element. The resistance element may be of any suitable type, such as wire-wound, carbon film, thick metal or metal oxide film or thin metal or metal oxide film.
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