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 over a repetitive cycle;
a programmable, digital memory;
means for loading said memory with a program of digital signals representative of desired temperatures for different times over said repetitive time cycle, circuitry for applying the output of the clock to the memory to generate a digital electric signal representative of the desired temperature at the instant time;
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 differences.
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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 conrol signal. A display provides a read-out of time and temperature and is used along with keyboard or the like in programming the memory.
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Citations
14 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 over a repetitive cycle;
a programmable, digital memory;
means for loading said memory with a program of digital signals representative of desired temperatures for different times over said repetitive time cycle, circuitry for applying the output of the clock to the memory to generate a digital electric signal representative of the desired temperature at the instant time;
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 differences. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- 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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10. 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 program of digital signals representative of desired temperatures for different times over said repetitive time cycle;
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; 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 (11, 12, 13, 14)
- means for generating a digital electrical signal representative of the ambient temperature on the thermostat;
Specification