Non-linear potentiometer coil - has radial contact paths between inner and outer coils, or circular contact path for special wiper

摘要

The non linear resistance for e.g. potentiometer switch, is made from resistive material in strip form, wound into a coil (1) and supported on a backing plate (2), so that the positive pole of an applied voltage is connected to the outer turn, and the negative pole connected to the innermost turn. A resistor is inserted in series between the negative pole and the end of the innermost turn, having a resistance which is proportional to the square of the radius of the innermost turn. Axial contact paths (4, 5, 6) for the wiper arm can be machined along the diameters, or for an alternative wiper system, a circular contact path (7) can be located between the innermost and outermost turns.