| 摘要 |
<p>A programmable thermostat for an air conditioning system having a heating system and a cooling system includes a sensor for sensing the ambient temperature, a timer for generating the current time of day, a memory for storing a plurality of program times, and a heating and a cooling control temperature corresponding to each program time. The memory also stores a first temperature span associated with the heating control temperatures and a second temperature span associated with the cooling control temperatures. The programmable thermostat controls the on/off state of the heating and cooling systems in response to (1) a comparison of the current time of day with the program times and (2) a comparison of the current ambient temperature with the current first and second temperature spans. These comparisons generate a switching control signal for controlling the on/off states of the heating and cooling systems. An alternation controller includes a first adjustor for adjusting the first temperature span prior to a changeover from the cooling system to the heating system. A second adjustor adjusts the second temperature span prior to the change-over from the heating system to the cooling system. Cycling of the air conditioning system between the heating system and the cooling system is thereby prevented if the heating control temperature is near the cooling control temperature. …<IMAGE>… </p> |
