Rotational type variable resistor

摘要

A rotational type variable resistor includes a base plate having an arcuate resistance element and an arcuate electrode formed on one surface thereof. A shaft adapted to be connected to the control member is rotatably mounted in the housing and carries a pair of brushes which are disposed in sliding engagement with the resistance member and the electrode. The resistance element is formed from a first resistance layer deposited on the base plate between a pair of copper foil electrodes. A silver paste is disposed between the copper foil electrodes and the opposite ends of the first resistance layer and a second resistance layer is formed which completely overlies the first resistance layer and the copper foil electrodes. The arcuate electrode includes a first layer of copper foil disposed on the surface of the substrate. A silver paste is coated on the upper surface of the copper foil and a third resistance layer is disposed on the surface of the silver paste, and a fourth resistance layer covers the third resistance layer. The resistivity of the first and third layers differs from the resistivity of the second and fourth layers.