Abstract: A wiper assembly for a potentiometer, particularly a rotary potentiometer having a rotor for carrying the wiper assembly along a resistive element, includes a metal plate attached to the rotor. A strip of metal formed integrally with the plate is bent back over itself out of the plane of the plate to form a cantilevered spring arm having a free end. Attached to the free end is an array of resilient, conductive wires arranged in a parallel, side-by-side relationship, each of the wires forming a resilient, cantilevered wiper finger. The spring arm and the array of wire wiper fingers attached to it form a hybrid wiper arm assembly. Preferably, the plate includes a first such hybrid wiper arm assembly arranged to function as a wiper for the resistive element in the potentiometer, and a second such wiper arm assembly arranged to function as a wiper for a conductive collector element in the potentiometer.

Abstract: An improved resistive element comprises a film-type resistive layer applied to an insulative substrate and then fired. An array of discrete, spaced apart islands of predominantly conductive material is then applied to the resistive layer in a repetitive pattern having predetermined inter-island spacing. The islands have a conductivity that is substantially greater than the conductivity of the resistive layer. Preferably, the islands are of substantially uniform shape and size. In one preferred embodiment, the islands are formed of a conductive thick film ink that is screen-printed onto a cermet resistive layer through an appropriate mask, and then fired. In another preferred embodiment, the islands are formed of a conductive metal that is applied to the resistive layer by vapor deposition, sputtering, or ion implantation through a suitable mask.

Abstract: A contact for a rotary action variable resistor is formed of a length of wire coiled into a flattened, substantially annular spiral, with a wiper element provided by a radial protuberance on the spiral. A first embodiment has a protuberance along each of a first pair of diametrically-opposed radii. The spiral is eccentrically mounted on a substantially circular support plate, with one protuberance extending close to the peripheral edge thereof, and the other protuberance closer to the center of the plate. The spiral is attached to the plate along a second pair of diametrically-opposed radii approximately 90 degrees displaced from the first pair. The spiral is sloped so that the distance between the plate and the spiral gradually increases from the attachment radii to the protuberances. The protuberance near the edge of the plate is a resistive element wiper, and the protuberance nearer the center is the collector wiper.

Abstract: An improved resistive element comprises a film-type resistive layer applied to an insulative substrate and then fired. An array of discrete, spaced apart islands of predominantly conductive material is then applied to the resistive layer in a repetitive pattern having predetermined inter-island spacing. The islands have a conductivity that is substantially greater than the conductivity of the resistive layer. Preferably, the islands are of substantially uniform shape and size. In one preferred embodiment, the islands are formed of a conductive thick film ink that is screen-printed onto a cermet resistive layer through an appropriate mask, and then fired. In another preferred embodiment, the islands are formed of a conductive metal that is applied to the resistive layer by vapor deposition, sputtering, or ion implantation through a suitable mask.