| 摘要 |
The invention relates to a variable electric resistor, comprising a contact track having at least two contact regions separated from each other by a gap, each having an associated electric resistor and at last one contact that can be moved along the contract track and is configured as a grinder and has at least one contact surface disposed toward the contact track, the geometry of the gap and the contact surface being configured such that the grinder is initially in electrical contact with a first contact region adjacent to the gap upon a movement along the contact track in the region of the gap, is subsequently in electric contact with both contact regions simultaneously, and in further progression of the movement is in electrical contact with the second contact region only, characterized according to a first embodiment of the invention in that the contact surface of the grinder has a convex curvature and is immersed into said gap when the grinder moves in the region of the gap, wherein the width and the depth of the gap and the curvature of the contact surface are aligned to each other such that a distance remains within the gap between the contact surface and the surface of the carrier material at the maximum immersion depth of the grinder into the center of the gap. An alternative embodiment of the invention provides that the contact surface of the grinder has at least two contact points positioned in a plane, the distance between the contact points being greater, in the direction of the movement of the grinder, than the width of the gap. |
