Abstract: The invention provides new potentiometer-type function generators that have (1) a resistance element having a two-dimensional contact surface with boundaries arranged so that a non-uniform voltage distribution is produced when the resistance element is electrified and (2) a contact member which is mounted so as to permit relative movement in two different directions between it and the contact surface of the resistance element.

Abstract: A heating regulator which is responsive to effective outdoor temperatures and the temperature of a heated fluid supplied by a boiler. The regulator has an adjustably positionable pointer which represents a characteristic curve. The regulator includes three slide members with the pointer being pivotally mounted on one of the slide members for a translatory movement therewith and pivotal movement relative thereto. Two potentiometers are operated by two of the slide members and one of the slide members actuates the third slide member which in turn effects pivotal movement of the pointer.