Electronic thermostat

A thermostat for generating control signals for a temperature modifying device, comprising:

• means for generating a digital electrical signal representative of the ambient temperature on the thermostat;
• means for generating a digital electrical signal representative of the time within a repetitive time cycle;
• a programmable digital memory;
• means for loading said memory with a plurality of separate programs each comprising digital signals representating desired temperature at particular times over a repetitive time cycle;
• means for selecting one of said plurality of programs;
• circuit means for interrogating said memory with said digital time signal to generate a digital signal representative of the desired temperature at the existing time as stored in said selected program;
• and a comparator operative to receive the digital signal representative of the ambient temperature on the thermostat and the digital signal representative of the desired temperature, and to provide a control signal to said temperature modifying device.

A thermostat for generating control signals for a temperature modifying device comprising:

• means for generating a digital electrical signal representative of the ambient temperature on the thermostat;
• manually accessible means for storing a plurality of time/temperature schedules in a programmable digital memory, said schedules providing a digital electrical signal representative of desired temperatures for different times within the interval defined by each schedule;
• means for generating a digital electrical signal representative of time;
• comparator means having one input coupled to said ambient temperature generator means;
• interface means coupled to said digital time generating means operative to selectively couple one of the schedules to the other input of said comparator;
• and
• means for coupling the output of said comparator to said temperature modifying device.