Abstract: According to various aspects, exemplary embodiments are disclosed of a thermostat that includes a charge pump configured to provide a charge pump supply voltage relative to a signal ground of the charge pump. One or more diodes are connected between the charge pump and the signal ground. The one or more diodes are configured to provide a forward voltage drop to increase the charge pump supply voltage.

Abstract: A stepper-motor gas valve control is disclosed that includes a main diaphragm in a chamber that controllably displaces a valve relative to an opening in response to changes in pressure, to adjust fuel flow through the valve. A servo-regulator diaphragm is provided to regulate flow to the main diaphragm, to thereby control the rate of fuel flow. A stepper motor is configured to move in a stepwise manner to displace the servo-regulator diaphragm, to control fluid flow to the main diaphragm. A controller mounted on the stepper-motor regulated gas valve control receives and converts an input control signal from a heating system to a reference value between 0 and 5 volts, and selects a corresponding motor step value. The control responsively moves the stepper-motor in a step wise manner to displace the servo-regulator diaphragm and thereby regulates the rate of fuel flow through the valve.