Electronic thermostat
First Claim
1. A thermostat for controlling the application of electrical power to a temperature modifying load, comprising:
- means for generating an electrical signal having a characteristic which varies as a function of the ambient temperature on the thermostat;
a clock operative to generate digital electrical signals having values representative of real time;
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, circuitry for applying the output of the clock to the memory to generate a digital electric signal representative of the desired temperature at a particular time as stored in said selected program;
means for receiving the electrical signal having a characteristic which is a function of ambient temperature and the output of the memory and for generating a control signal for said temperature modifying devices as a function of their difference.
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Accused Products
Abstract
A thermostat for generating control signals for a furnace, air conditioner, or the like, employs a constant frequency, periodically alternating electrical source and an oscillator incorporating an element having a thermal-sensitive electrical characteristic so the oscillator frequency varies as a function of the ambient temperature. A comparator receives the two outputs and generates a signal representative of the ambient temperature. The stable output is also provided to dividing circuits to generate a signal representative of the time that is used to interrogate a digital memory storing a desired temperature-time program for the thermostat for a repetitive period, such as a week or month. The ambient temperature signal is compared with the desired temperature signal to generate an output control signal. A display provides a read-out of time and temperature and is used along with a keyboard or the like in programming the memory.
235 Citations
17 Claims
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1. A thermostat for controlling the application of electrical power to a temperature modifying load, comprising:
- means for generating an electrical signal having a characteristic which varies as a function of the ambient temperature on the thermostat;
a clock operative to generate digital electrical signals having values representative of real time;
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, circuitry for applying the output of the clock to the memory to generate a digital electric signal representative of the desired temperature at a particular time as stored in said selected program;
means for receiving the electrical signal having a characteristic which is a function of ambient temperature and the output of the memory and for generating a control signal for said temperature modifying devices as a function of their difference. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 14)
- means for generating an electrical signal having a characteristic which varies as a function of the ambient temperature on the thermostat;
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9. 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. - View Dependent Claims (10, 11, 12, 13)
- means for generating a digital electrical signal representative of the ambient temperature on the thermostat;
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15. A thermostat for generating control signals for a temperature modifying device comprising:
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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. - View Dependent Claims (16, 17)
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Specification