Patent ID: 8752577

Claim:
A stepper-motor regulated gas valve, comprising: an inlet, an outlet, and a flow path therebetween; a main diaphragm coupled to and configured to displace a main valve relative to a main valve opening in response to changes in pressure in a main diaphragm chamber; a servo-regulator diaphragm configured to regulate fluid flow to the main diaphragm chamber, to control a rate of fluid flow through the main valve opening; a stepper motor coupled to the servo-regulator diaphragm and configured to move in a stepwise manner to displace the servo-regulator diaphragm to regulate fluid flow into the main diaphragm chamber; and a control circuit coupled to the stepper motor for adapting the gas valve to use the same current signal control input for modulating fuel flow as, and to provide the same outlet pressure as, any one of a plurality of different gas valve types that receive a current signal control input but in which a stepper motor is not used to perform fuel regulation, the stepper-motor regulated gas valve being adaptable by the control circuit for use in a fuel-fired heating system in place of any one of the plurality of different gas valve types, the control circuit further configured to: receive a current signal control input configured to produce a desired outlet pressure in a selected one of the plurality of different gas valve types, convert the received current signal control input to a reference value having a voltage of between 0 and 5 volts, using the reference value, determine a stepper motor step value for regulating the fluid flow to produce the desired outlet pressure, and energize the stepper motor according to the determined motor step value.