Abstract: A method of accommodating an element in a building equipment component. The presence of the element may be detected, and whether the element is required may be determined. The building equipment component may be operated if the element is present and required, or if the element not required. If the element is absent but required, the building equipment component may be stopped. In some instances, the building equipment component may include a required first sensor, and the element may be an optional second sensor.

Abstract: A direct current to direct current voltage converter (DC-DC converter) in accordance with the invention comprises a transformer coupled with a voltage source and a self-starting oscillator that includes a secondary winding of the transformer, a capacitor; and a first switch coupled to conduct current from the DC source via a primary winding of the transformer. The first switch is a normally closed switch. The DC-DC converter also comprises a second switch coupled to conduct current in a parallel path with the first switch, the second switch being a normally open switch having a lower saturation resistance than the first switch.

Abstract: A water heater performance monitoring device for monitoring whether a water heater is functioning optimally or whether it requires service. The device uses maximum heating rates taken from a plurality of measured heating rates to determine if the performance of the water heater has degraded from a threshold performance level. A water heater performance monitoring device can reduce the number of false alarms that occur regarding the need for water heater service by filtering out temporary factors, lasting less than a time cycle, which affect heating rate of water in the water heater. This can save users time and money by reducing unnecessary water heater inspections.

Abstract: A low cost flame sensing system having at last one floating point. For instance, the system may have two grounds. There may be a flame sensing rod for detecting a flame which has a model circuit which appears upon the existence of the flame proximate to the sensing rod. The sensing rod may function without an explicit or dedicated excitation source connected to it. There may be diagnostics in the system for detecting leakage or shorts of the sensing rod to ground. Also, the system may have AC grounding phase detection.

Abstract: A system for adjusting a bias voltage of a flame sensing system. The system may use pulse width modulation to adjust the bias voltage. The system may have a flame sensing rod that conveys an electrical equivalent circuit of a flame presence to a detector via low pass filter. An excitation voltage may be conveyed via a DC blocking mechanism to the sensing rod. A pulse width modulation signal may be conveyed via a bias resistor to a node of the low pass filter and the detector. The input of an A/D converter may be that of the detector for flame signals. Also, leakages between the node of the A/D converter connection and the voltage source and/or ground may be detected and compensated. Further, leakage of the DC blocking mechanism may be minimized.

Abstract: A flame sensing system having a flame rod, a signal generator, a signal measurement circuit, and a controller, where the frequency and/or amplitude of the excitation signal may be variable. The signal measurement circuit may include a bias circuitry that references the flame signal to a voltage, a capacitor that varies the filtration, an AC coupling capacitor, a current limiting resistor, and a low-pass filter. The system may determine the flame-sensing rod contamination, the stray capacitance of the flame sensing system, and compensate for stray capacitance in the flame sensing system. The flame model may include a circuit that simulates a flame in the presence of the sensing rod, and another circuit that simulates a contact surface between the flame and the sensing rod.

Abstract: A signal generation system for flame ignition and sensing. The ignition signal generation is adaptive for improving flame ignition while eliminating excess energy usage. High voltage signals for flame sensing may also be provided. If more energy or speed is needed for ignition signal generation, then the flame sensing signal generation portion may be disabled to increase the amount of available energy. Adaptation for ignition signal generation may be guided by the results of flame sensing. The flame sensing voltage may be regulated based on the flame current strength. The flame current may be controlled within an optimum range to reduce rod contamination rate and yet provide reliable flame sensing when the rod contamination built up. The adaptation may be algorithmic-based with the facilitation of a microcontroller. The system may provide the high voltage signals from a low voltage power supply, such as that of 24 VAC.

Abstract: A water heater performance monitoring device for monitoring whether a water heater is functioning optimally or whether it requires service. The device uses maximum heating rates taken from a plurality of measured heating rates to determine if the performance of the water heater has degraded from a threshold performance level. A water heater performance monitoring device can reduce the number of false alarms that occur regarding the need for water heater service by filtering out temporary factors, lasting less than a time cycle, which affect heating rate of water in the water heater. This can save users time and money by reducing unnecessary water heater inspections.

Abstract: A method for determining the presence of a leak in a water heater unit comprising a storage tank is presented. The present invention involves mounting one heating sensor on the lower half of the tank and another heating sensor on the upper half of the tank. Readings from both sensors are taken and compared to determine if the water heater tank has reached a steady state; if so, the cooling rate of the tank is determined. This cooling rate is compared to the historical natural cooling rate of the system, and based on the comparison a determination is made on the presence of a leak.

Abstract: A fail-safe apparatus for controlling fluid flow through a series arrangement of first and second solenoid-controlled valves is provided. The fail-safe apparatus includes fail-safe circuitry for controlling the operation of the first and second solenoid-controlled valves between unactuated and actuated states. Based on a given duty cycle, the fail-safe circuitry selects, actuates, deactuates, and/or maintains in the actuated or unactuated state one or both of the first and second solenoid-controlled valves. To facilitate such control, the fail-safe circuitry may include a switch operable to couple an input voltage across the first solenoid-controlled valve to cause a first current to flow therein. The fail-safe circuitry may also include an energy-transfer device coupled between the first and second solenoid-controlled valves.

Abstract: A method of verifying proper operation of an electromagnetic valve. The method includes providing a mechanism to effect opening of the valve, verifying that the valve opened as a result of employing the mechanism to effect opening of the valve and after verifying the valve opened, signaling the valve to close after a first period of time has elapsed. The method further includes, after signaling the valve to close, signaling the valve to re-open after a second period of time has elapsed and detecting the occurrence or non-occurrence of an event associated with the closing or re-opening of the valve.

Abstract: A circuit in accordance with the invention includes a safety switch device coupled with, and between, a thermally activated voltage source and a primary switch. The circuit also includes a safety switch control circuit coupled with the safety switch device and a controller circuit; and a voltage generation circuit for turning on the safety switch device. The voltage generation circuit is coupled with the safety switch control circuit, the controller circuit and the safety switch device, such that the controller circuit substantially controls operation of the voltage generation circuit, the safety switch control circuit, and a primary switch circuit that includes the primary switch.

Abstract: An improved heater and method of controlling the same is provided. The water heater has the combination of a tank for holding water, a heater for heating the water, a controller having logic to regulate the heater, and first and second sensors. Each of the sensors detects the water temperature at different areas within the water heater. The sensors also provide the controller with signals corresponding to the detected water temperature. In response to these signals, the controller regulates the heater when at least one of the signals of the first and second sensors satisfies at least one predetermined state condition.

Abstract: A self-sustaining control for a heating system, having conventional operational modes and pilot burner assembly, is disclosed. A controller directs operation in accordance with a need-based protocol and monitors the condition of a storage device, which provides system power during the stand-by or off mode under normal conditions. A thermo-electric device is in thermal communication with the pilot burner assembly and powers the system whenever the pilot is lit. Regardless of heat need, the controller directs operation in a pilot-on mode, in lieu of an off mode, whenever the storage device is compromised.

Abstract: A fail-safe apparatus for controlling fluid flow through a series arrangement of first and second solenoid-controlled valves is provided. The fail-safe apparatus includes fail-safe circuitry for controlling the operation of the first and second solenoid-controlled valves between unactuated and actuated states. Based on a given duty cycle, the fail-safe circuitry selects, actuates, deactuates, and/or maintains in the actuated or unactuated state one or both of the first and second solenoid-controlled valves. To facilitate such control, the fail-safe circuitry may include a switch operable to couple an input voltage across the first solenoid-controlled valve to cause a first current to flow therein. The fail-safe circuitry may also include an energy-transfer device coupled between the first and second solenoid-controlled valves.

Abstract: A method and apparatus for determining a health status of a water heating device is disclosed. The water heating device may have a controller that incorporates logic to regulate the heater responsive to water temperatures detected at different areas within the water heating device by first and second sensors. Unfortunately, the first and second sensors may fail. To detect fault conditions or otherwise determine the heath status of the water heating device, a logic unit in the controller may perform a test on the first and/or second sensors so as to provide a test output. The logic unit may also determine whether the test output satisfies one or more predetermined thresholds. These predetermined thresholds may be indicative of a properly-functioning sensor. When the test output does not satisfy the at least one predetermined threshold, the logic unit may then set a fault condition indicative of improperly functioning sensors.

Abstract: A valve control circuit in accordance with the invention comprises a direct current (DC) voltage source and a DC-DC step-up converter coupled with the DC voltage source. The circuit also comprises a programmable controller coupled with the DC-DC converter, a first valve control switch coupled with the DC source and the controller, and a first valve coupled with the first valve control switch. The circuit further comprises a valve-picking circuit coupled with the controller such that a current source of the valve-picking circuit is selectively coupled with the first valve control switch to open the first valve in response to electrical signals from the controller.

Abstract: A direct current to direct current voltage converter (DC-DC converter) in accordance with the invention comprises a transformer coupled with a voltage source and a self-starting oscillator that includes a secondary winding of the transformer, a capacitor; and a first switch coupled to conduct current from the DC source via a primary winding of the transformer. The first switch is a normally closed switch. The DC-DC converter also comprises a second switch coupled to conduct current in a parallel path with the first switch, the second switch being a normally open switch having a lower saturation resistance than the first switch.

Abstract: A self-sustaining control for a heating system, having conventional operational modes and pilot burner assembly, is disclosed. A controller directs operation in accordance with a need-based protocol and monitors the condition of a storage device, which provides system power during the stand-by or off mode under normal conditions. A thermo-electric device is in thermal communication with the pilot burner assembly and powers the system whenever the pilot is lit. Regardless of heat need, the controller directs operation in a pilot-on mode, in lieu of an off mode, whenever the storage device is compromised.

Abstract: A valve control circuit in accordance with the invention comprises a direct current (DC) voltage source and a DC-DC step-up converter coupled with the DC voltage source. The circuit also comprises a programmable controller coupled with the DC-DC converter, a first valve control switch coupled with the DC source and the controller, and a first valve coupled with the first valve control switch. The circuit further comprises a valve-picking circuit coupled with the controller such that a current source of the valve-picking circuit is selectively coupled with the first valve control switch to open the first valve in response to electrical signals from the controller.