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 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 desired 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 desired heating level, and generating a gas valve control signal corresponding to the desired 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 desired heating level.
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 desired 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 desired heating level.
33 Citations
20 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 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 desired 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 desired heating level, and generating a gas valve control signal corresponding to the desired 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 desired heating level. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. 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 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 desired 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 desired heating level, and generating a gas valve control signal corresponding to the desired 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 desired heating level. - View Dependent Claims (10, 11, 12, 13, 14, 15, 16, 17, 19)
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18. The controller of claim 18, wherein the microprocessor is configured to determine the number of steps the stepper motor must move by selecting a motor step value from a look-up table corresponding to the desired heating level.
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20. A controller in combination with a stepper-motor operated gas valve configured to vary the gas flow rate for varying the level of heating operation, the controller and stepper-motor operated gas valve combination comprising:
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a valve element movable relative to a valve opening in the gas valve; a main diaphragm chamber disposed in the gas valve, a main diaphragm disposed in the main diaphragm chamber and coupled to the valve element, the main diaphragm being configured to controllably displace the valve element relative to the valve opening in response to changes in gas pressure acting against the main diaphragm; a servo-regulator diaphragm configured to regulate flow of gas to the main diaphragm chamber that acts against the main diaphragm, to thereby adjust the valve element to vary the flow rate of gas through the valve opening; a stepper motor configured to move in a stepwise manner to displace the servo-regulator diaphragm for varying the flow of gas to the diaphragm chamber, to thereby control the rate of gas flow through the valve opening; a first terminal disposed on the gas valve configured to receive a control signal corresponding to a desired gas flow rate for establishing a desired level of heating operation; a first terminal on the controller configured to receive a thermostat signal requesting heating operation; an electronic memory associated with the controller; 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 stepper motor operated gas valve to displace the servo-regulator diaphragm to establish gas flow 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 desired 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 number of steps the stepper motor must move to displace the servo-regulator diaphragm and vary the gas flow rate corresponding to the desired heating level, and to generate a control signal corresponding to the determined number of steps for the stepper motor to adjust the servo-regulator diaphragm and vary the gas flow rate corresponding to the desired heating level.
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Specification