Digital thermostat

摘要

An energy conserving thermostatic control system having digitally implemented control functions for use with a heating and/or air conditioning system is disclosed. The digital thermostat includes an LCD data display for simultaneously displaying present time and ambient temperature. Slide switches are provided for setting and indicating set point information such as day temperature, night temperature, night-to-day transition time, and day-to-night transition time. The switch contacts of each slide switch are multiplexed to the display driver conductors for conveying time and temperature set point data during time and temperature scan intervals which alternate with a display interval. Strobe signals which are applied to the driver conductors are counted during the alternate scan intervals for selecting a day temperature different from a night temperature, for selecting the times which divide night from day and for providing set-back to night temperature during a predetermined time of the day. A day-skipper circuit inhibits set-back on selected days. A power divider circuit is provided which permits wire-for-wire substitution of the digital thermostat for a conventional electro-mechanical thermostat.