Abstract: A time proportional control means, shown as a temperature control system, utilizes an expanded time constant arrangement with a unidirectional type of digital counter. The control system also utilizes a pulse generating means that is linked to the set point control for the system. Any substantial change of the set point causes the pulse generating means to generate pulses that are used by a pulse responsive circuit to insure that the counter for the system is adjusted to cause the output of the system to correspond with the new set point position.

Abstract: A thermostat adapted for use in an electrical control system for controlling temperature conditioning apparatus has at least two circuit adjusting members or potentiometers comprising a resistance circuit board mounted on a base and a pair of pivotally mounted wiper supporting members for cooperating with the resistance circuit. Each of the members are pivoted on the same pivot and the first member has an open area through which the wiper of the second member mounted adjacent thereto protrudes to cooperate with the electrical circuit board to provide a compact unit. A pair of adjusting members are horizontally movably attached to the base to cooperate with the ends of the pivotal selector members to provide for pivotal movement of the selector members upon straight line movement of the adjusting member.