Air conditioning thermostatic control system having modular inclusion of

Abstract

Methods and circuits for providing auxiliary or remote temperature set or set-back capability in comparator-based thermostatic temperature control systems. In particular, the invention is applicable to thermostatic control systems of the general type including a temperature-responsive source for producing a temperature-dependent voltage as a function of sensed temperature, a reference voltage source for establishing a temperature set point, a voltage comparator having a comparison input and a reference input for producing a control output signal for energizing a thermal conditioning element when voltages applied respectively to the comparison and reference inputs have at least a predetermined relationship with respect to each other, an electrical connection between said temperature-responsive voltage source and the comparison input, and an electrical connection between the reference voltage source and the reference input. For remote temperature setting, the set point voltage applied to the comparator reference input is forced towards a particular value representative of a particular temperature by employing an auxiliary reference voltage source having an output impedance lower than that of the reference voltage source. Preferably, the auxiliary reference voltage source includes, as an output element, a unity-gain operational amplifier.