Electronic thermostat with a stored program of desired temperatures and predetermined maximum and minimum temperatures

A thermostat for use in a building having a heating means and a cooling means, the thermostat operable in a heating mode to generate an energizing signal for the heating means and operable in a cooling mode to generate an energizing signal for the cooling means, the thermostat comprising:

• means for measuring the ambient temperature within the building;
• programming means for selectively storing either a program of temperatures for the building over a repetitive time cycle in a heating mode or a program of temperatures for the building over a repetitive time cycle in a cooling mode;
• a clock for generating signals representative of the present time;
• means connected to said means for selectively storing a program of temperatures and said clock for generating a programmed temperature signal for the present time;
• means connected to said programming means for initially setting a control temperature equal to the programmed temperature and setting a mode to the programmed mode upon storing a program of temperatures;
• means for comparing the ambient temperature with the control temperature;
• means operable only in said heating mode for generating an energizing signal for said heating means if said actual temperature is less than said control temperature;
• means operable only in said heating mode if said actual temperature is greater than a first predetermined temperature for entering said cooling mode and setting said control temperature equal to said programmed temperature if programmed in said cooling mode and for entering said cooling mode and setting said control temperature equal to a first temperature having a predetermined relationship to said programmed temperature if programmed in said heating mode;
• means operable only in said cooling mode for generating an energizing signal for said cooling means of said actual temperature is greater than said control temperature;
• and
• means operable only in said cooling mode if said actual temperature is less than a second predetermined temperature, said second predetermined temperature being less than said first predetermined temperature, for entering said heating mode and setting said control temperature equal to said programmed temperature if programmed in said heating mode and for entering said heating mode and setting said control temperature to a second temperature having a predetermined relationship to said programmed temperature if programmed in said cooling mode.