Stepper motor gas valve and method of control
First Claim
1. A controller for a variable heating system having a variable rate gas valve configured to adjust a gas flow rate to vary the level of heating operation, the controller comprising:
- a first terminal configured to receive a thermostat signal requesting heating operation;
an electronic memory; and
a microprocessor in communication with the electronic memory and the first terminal, the microprocessor being configured to detect the presence of a thermostat signal requesting heating at the first terminal and to generate a control signal for the variable rate gas valve to operate the variable rate gas valve for establishing heating operation, the microprocessor including a programmable read-only-memory encoded with an instruction to store in the electronic memory a time duration during which the microprocessor detects the presence of a thermostat signal requesting heating, and further encoded with an instruction operable to determine a predetermined heating level based on the stored time duration, wherein the microprocessor is configured to respond to the detection of a thermostat signal requesting heating by determining the predetermined heating level, and generating a gas valve control signal corresponding to the predetermined heating level that is applied to the variable rate gas valve to adjust the variable rate gas valve to the gas flow rate corresponding to the predetermined heating level;
wherein the instruction is configured to determine a new predetermined heating level based on the following formula;
% change to prior capacity=(prior on-time(min)−
threshold on-time(min))×
5%.
5 Assignments
0 Petitions
Accused Products
Abstract
A controller for a variable heating system is operable to control a stepper motor operated gas valve to adjust gas flow to vary the heating level. The controller includes a first terminal for receiving a thermostat signal requesting heating, an electronic memory, and a microprocessor in communication with the electronic memory and first terminal. The microprocessor detects a thermostat signal requesting heating, and generates a control signal for the stepper motor to operate the gas valve. The microprocessor includes a programmable read-only-memory encoded with an instruction to store a time duration during which the microprocessor detects a thermostat signal requesting heating, and further encoded with an instruction operable to determine a predetermined heating level based on the stored time duration. The microprocessor responds to a thermostat signal requesting heating by determining the number of steps the motor must move to vary the gas flow corresponding to the predetermined heating level.
28 Citations
21 Claims
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1. A controller for a variable heating system having a variable rate gas valve configured to adjust a gas flow rate to vary the level of heating operation, the controller comprising:
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a first terminal configured to receive a thermostat signal requesting heating operation; an electronic memory; and a microprocessor in communication with the electronic memory and the first terminal, the microprocessor being configured to detect the presence of a thermostat signal requesting heating at the first terminal and to generate a control signal for the variable rate gas valve to operate the variable rate gas valve for establishing heating operation, the microprocessor including a programmable read-only-memory encoded with an instruction to store in the electronic memory a time duration during which the microprocessor detects the presence of a thermostat signal requesting heating, and further encoded with an instruction operable to determine a predetermined heating level based on the stored time duration, wherein the microprocessor is configured to respond to the detection of a thermostat signal requesting heating by determining the predetermined heating level, and generating a gas valve control signal corresponding to the predetermined heating level that is applied to the variable rate gas valve to adjust the variable rate gas valve to the gas flow rate corresponding to the predetermined heating level; wherein the instruction is configured to determine a new predetermined heating level based on the following formula;
% change to prior capacity=(prior on-time(min)−
threshold on-time(min))×
5%. - View Dependent Claims (2, 3)
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4. A controller for a variable heating system having a variable rate gas valve configured to adjust a gas flow rate to vary the level of heating operation, the controller comprising:
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a first terminal configured to receive a thermostat signal requesting heating operation; an electronic memory; and a microprocessor in communication with the electronic memory and the first terminal, the microprocessor being configured to detect the presence of a thermostat signal requesting heating at the first terminal and to generate a control signal for the variable rate gas valve to operate the variable rate gas valve for establishing heating operation, the microprocessor including a programmable read-only-memory encoded with an instruction to store in the electronic memory a time duration during which the microprocessor detects the presence of a thermostat signal requesting heating, and further encoded with an instruction operable to determine a predetermined heating level based on the stored time duration, wherein the microprocessor is configured to respond to the detection of a thermostat signal requesting heating by determining the predetermined heating level, and generating a gas valve control signal corresponding to the predetermined heating level that is applied to the variable rate gas valve to adjust the variable rate gas valve to the gas flow rate corresponding to the predetermined heating level; wherein the instruction is configured to determine a new predetermined heating level by decrementing the heating capacity level of the last heating cycle by a predetermined percentage for each minute the stored time duration of the signal requesting heating is less than a threshold time period. - View Dependent Claims (5, 6, 7)
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8. A controller for a variable heating system having a variable rate gas valve configured to adjust a gas flow rate to vary the level of heating operation, the controller comprising:
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a first terminal configured to receive a thermostat signal requesting heating operation; an electronic memory; and a microprocessor in communication with the electronic memory and the first terminal, the microprocessor being configured to detect the presence of a thermostat signal requesting heating at the first terminal and to generate a control signal for the variable rate gas valve to operate the variable rate gas valve for establishing heating operation, the microprocessor including a programmable read-only-memory encoded with an instruction to store in the electronic memory a time duration during which the microprocessor detects the presence of a thermostat signal requesting heating, and further encoded with an instruction operable to determine a predetermined heating level based on the stored time duration, wherein the microprocessor is configured to respond to the detection of a thermostat signal requesting heating by determining the predetermined heating level, and generating a gas valve control signal corresponding to the predetermined heating level that is applied to the variable rate gas valve to adiust the variable rate gas valve to the gas flow rate corresponding to the predetermined heating level; wherein the instruction is configured to determine a new predetermined heating level by incrementing the heating capacity level of the last heating cycle by a predetermined percentage for each minute the stored time duration of the signal requesting heating exceeds a threshold time period. - View Dependent Claims (9)
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10. A controller for a variable heating system having a variable rate gas valve configured to adjust a gas flow rate to vary the level of heating operation, the controller comprising:
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a first terminal configured to receive a thermostat signal requesting heating operation; an electronic memory; and a microprocessor in communication with the electronic memory and the first terminal, the microprocessor being configured to detect the presence of a thermostat signal requesting heating at the first terminal and to generate a control signal for the variable rate gas valve to operate the variable rate gas valve for establishing heating operation, the microprocessor including a programmable read-only-memory encoded with an instruction to store in the electronic memory a time duration during which the microprocessor detects the presence of a thermostat signal requesting heating, and further encoded with an instruction operable to determine a predetermined heating level based on the stored time duration, by decrementing the heating capacity level of the last heating cycle by a predetermined percentage for each minute that the stored time duration is less than a threshold time period, or by incrementing the heating capacity level of the last heating cycle by a predetermined percentage for each minute that the stored time duration exceeds a threshold time period, wherein the microprocessor is configured to respond to the detection of a thermostat signal requesting heating by determining the predetermined heating level, and generating a gas valve control signal corresponding to the predetermined heating level that is applied to the variable rate gas valve to adjust the variable rate gas valve to the gas flow rate corresponding to the predetermined heating level. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification