Electronically controlled programmable digital thermostat

Abstract

An electronic digital programmable wall thermostat system for controlling heating and cooling systems supplying an indoor area or space. The thermostat includes a digital clock, a display for displaying desired parameters of time and temperature and a data entry keyboard for programming the thermostat to maintain desired temperatures during selected time intervals. The heart of the system is a digital processor with memory, which responds to signals from a temperature sensing means which includes an analog to digital converter for controlling the heating and cooling systems in accordance with the sequence programmed therein. The system provides for conservation of energy by automatic system shutdown or setback when the heated or cooled space is unoccupied or during periods when activity in the space is minimal such as during sleeping hours. In a preferred embodiment, a single chip digital processor is used to control the operation of the thermostat system, the keyboard, display and temperature sensing means being selectively scanned from output terminals of the digital processor.