Electronic programmable thermostat for a heating and cooling system with an oscillation control mechanism

A method for controlling the operation of an air conditioning system including heating and cooling systems to thereby control the ambient temperature of a predetermined volume of space, the method comprising the steps of:

• (a) comparing the current time of day with program times stored in a memory to access corresponding current heating and cooling control temperatures stored in said memory, a first temperature span being associated with the heating control temperatures which first temperature span determines a first temperature for each program time at which said heating system is switched on and a second temperature for each program time at which said heating system is switched off and a second temperature span being associated with the cooling control temperatures which second temperature span determines a third temperature for each program time at which said cooling system is switched on and a fourth temperature for each program time at which said cooling system is switched off;
• (b) comparing the current ambient temperature in the predetermined volume of space which is sensed by a temperature sensor with the current first, second, third, and fourth temperatures;
• (c) generating a switching control signal for controlling the on/off state of said heating and cooling systems in response to the comparisons of steps (a) and (b);
• and
• (d) adjusting (1) at least the current third temperature prior to switching on said cooling system in response to the switching control signal after said heating system is switched off at the current second temperature or (2) at least the current first temperature prior to switching on said heating system in response to the switching control signal after said cooling system is switched off at the current fourth temperature.

A digital, programmable thermostat for an air conditioning system including a heating system and a cooling system which controls the ambient temperature of a predetermined volume of space, said thermostat comprising:

• memory means for storing a heating and a cooling control temperature, a first temperature span associated with the heating control temperature, which first temperature span determines a first temperature at which said heating system is switched on and a second temperature at which said heating system is switched off, and a second temperature span associated with the cooling control temperature, which second temperature span determines a third temperature at which said cooling system is switched on and a fourth temperature at which said cooling system is switched off;
• control means for selectively controlling the on/off state of said heating and cooling systems in response to a comparison of the ambient temperature and said first temperature, said second temperature, said third temperature, and said fourth temperature, to generate a switching control signal;
• sensor means for sensing the ambient temperature of the predetermined volume of space;
• and
• adjusting means for adjusting (1) at least the current third temperature prior to switching on said cooling system in response to the switching control signal after said heating system is switched off at the current second temperature or (2) at least the current first temperature prior to switching on said heating system in response to the switching control signal after said cooling system is switched off at the current fourth temperature.

An air conditioning system for controlling the ambient temperature of a predetermined volume of space and having a heating mode controlled by the on/off switching of a heating system and a cooling mode controlled by the on/off switching of a cooling system, said air conditioning system comprising:

• sensor means for sensing the ambient temperature of the predetermined volume of space;
• timing means for generating the current time of day;
• memory means for storing an operating program including a plurality of program times, a heating and a cooling control temperature corresponding to each program time, a first temperature span associated with the heating control temperatures which first temperature span determines a first temperature for each program time at which said heating system is switched on and a second temperature for each program time at which said heating system is switched off, and a second temperature span associated with the cooling control temperatures which second temperature span determines a third temperature for each program time at which said cooling system is switched on and a fourth temperature for each program time at which said cooling system is switched off;
• control means for selectively controlling the on/off state of said heating and cooling systems in response to (1) a comparison of the current time of day with the program times stored in said memory means to access the corresponding current heating and cooling control temperatures stored in said memory means and (2) a comparison of the current ambient temperature sensed by said sensor means with the current first, second, third, and fourth temperatures as determined by the current heating and cooling control temperatures and the first and second temperature spans to generate a switching control signal for controlling the on/off state of said heating and cooling systems;
• and
• adjusting control means for adjusting at least one of the first and second temperature spans in response to the switching control signal prior to an alternation from one of the heating and cooling modes to the other.