Abstract: A DC voltage-limiting circuit generally includes first, second, and third transistors. The first transistor is connected between a voltage input terminal and a voltage output terminal. The first transistor has a collector connected to the voltage input terminal, an emitter connected to the voltage output terminal, and a base connected to the voltage input terminal via a first resistor. The second transistor has a base connected to the voltage input terminal via a first voltage regulator and a second resistor, a collector connected to the base of the first transistor, and an emitter connected to the voltage output terminal. The third transistor has a collector connected to the base of the first transistor via a third resistor, an emitter grounded, and a base connected to the voltage output terminal via a second voltage regulator and a fourth resistor.

Abstract: A system includes a visual inspection system and an image analysis system. The visual inspection system includes an inspection camera that captures images from within an interior of at least one of a utility line and a tunnel for installing a utility line, and a first communication interface that communicates image data corresponding to the images. The image analysis system includes a second communication interface that receives the image data from the visual inspection system, a model adaptation module that modifies a classifier model based on at least one of feedback data and training data, and a classifier module that implements the classifier model to identify a plurality of features in the image data corresponding to defects and that modifies the image data according to the identified plurality of features. The defects include at least one of a cross-bore, a lateral pipe, and an imperfection.

Abstract: A monitoring system for monitoring a heating, ventilation, and air conditioning (HVAC) system of a building includes a monitoring server. The monitoring server is configured to receive an aggregate control line current value from a monitoring device. The aggregate control line current value represents a total current flowing through control lines used by a thermostat to command the HVAC system. The monitoring server is configured to determine a commanded operating mode of the HVAC system in response to the aggregate control line current value. Operating modes of the HVAC system include at least one of an idle mode and an ON mode. The monitoring server is configured to analyze a system condition of the HVAC system based on the determined commanded operating mode.

Abstract: An electronic control unit for controlling an electronic controlled multistage gas valve (MGV) for adjusting gas flow to a gas fired appliance. In an exemplary embodiment, an electronic control unit generally includes an integrated furnace control (IFC) unit, a multistage gas valve control (MGVC) unit electronically coupled to the IFC unit, and a coil electronically coupled to the MGVC unit. The IFC unit is operable for providing at least one power supply signal over a first communication line and at least one pulse width modulated (PWM) duty cycle signal over a second communication line to the MGVC unit for controlling at least one of energizing and de-energizing of the coil. The electronic controlled MGV is adapted to move in response to a magnetic field generated by the coil.

Abstract: A control system includes a remote temperature sensor configured to wirelessly communicate a signal indicative of a space temperature, and a return air temperature sensor configured to output a signal indicative of a temperature of return airflow within an air conditioning/heating unit. The system further includes a controller segregated from the space that is responsive to the signals from the sensors for determining a working sensed temperature based upon a temperature value associated with the return air sensor and at least one temperature value associated with at least one remote temperature sensor. The controller is configured to compare the working sensed temperature to a set-point temperature and responsively generate a command signal to activate the air conditioning or heating unit to control temperature relative to a set-point. The controller controls the air conditioning/heating unit at all times based upon the temperature value associated with the return air sensor.

Abstract: Exemplary embodiments or implementations are disclosed of methods, apparatus, and systems for operating motors in variable speed situations. In an exemplary implementation, a method of controlling a variable-speed motor includes defining a control duration as a predetermined number of cycles of a multiple-phase power supply. Each speed in a range of speeds is defined by a corresponding number of the cycles of the control duration. Power is provided to the motor from the power supply at a selected one of the speeds, by enabling input from the power supply for the number of the cycles of the control duration corresponding to the selected speed.

Abstract: A stator for a polyphase dynamoelectric machine includes a stator core and windings positioned about the stator core. The windings include at least a first phase winding and a second phase winding. The first phase winding is formed of at least one electrical conductor material that is not present in the second phase winding.

Abstract: A wrench having a collection of moveably positionable jaws which is pivotally affixed to a handle is described. The wrench can include the use of one or more regions of friction material located about an enclosed gripping region. The wrench finds particular application in drilling industries.

Abstract: Exemplary embodiments are disclosed of touchscreen devices for thermostats and other electronic devices. In an exemplary embodiment, a capacitive touchscreen device includes a touchscreen having touch regions. Each touch region is coupled with at least one first capacitor and at least one second capacitor. The second capacitors are connected in parallel and have smaller capacitance than the first capacitors. The capacitive touchscreen device may be configured to be operable in a standby mode in which the second capacitors are charged and an active mode in which the first capacitors are charged.

Abstract: A soil pipe cutting tool is described. The tool includes a telescoping housing assembly, a feedscrew in threaded engagement with the housing assembly, and a cutting chain. The cutting tool can be powered by an impact driver. Also described are rotary powered tools. In certain versions, the tools include torque limiting provisions to prevent transfer of excessively high levels of torque to a working end of the tool. Various methods of use are also described.

Abstract: A gas flow controller for use in a gas fired apparatus includes an actuator, a pilot valve operably connected to the actuator, a main burner valve, and a flow controller valve operably connected to the actuator. The pilot valve is moveable from a closed position to an open position by actuation of the actuator to provide selective fluid communication between a gas inlet and a first fluid chamber. The main burner valve provides selective fluid communication between the first fluid chamber and a main burner outlet. The flow controller valve is moveable from a closed position to an open position by actuation of the actuator to provide selective fluid communication between the gas inlet and a back side of the main burner valve to maintain the main burner valve in a closed position when the pilot valve is in the open position.

Abstract: A system and method for monitoring a heating, ventilation, or air conditioning (HVAC) system of a building is provided. A monitoring server, located remotely from the building, receives operating parameter data from a monitoring device at the building that measures an operating parameter of the HVAC system. The monitoring server generates a plurality of data clusters from the operating parameter data, each data cluster corresponding to operating parameter data generated during steady-state operation of the HVAC system. The monitoring server calculates an average operating parameter value for each data cluster. The monitoring server calculates normalized operating parameter values based on normalizing the average operating parameter values for the data clusters over a predetermined normalization time period. The monitoring server compares the normalized operating parameter values with a threshold.

Abstract: A smart energy control module for a water heater includes a switching module that receives a voltage supply and outputs the voltage supply to the water heater. A communication module communicates with at least one of an energy meter and an energy network external to the water heater and the control module. The control module is mounted on the water heater. The voltage supply passes at least one of through and adjacent to the control module. The control module determines at least one operating characteristic of the water heater based on the voltage supply and selectively actuates the switching module to turn on and turn off the voltage supply to the water heater in response to the operating characteristic and information received from the at least one of the energy meter and the energy network.

Abstract: A first tracking module increments a first period of time when a heating, ventilation, or air conditioning (HVAC) system of a building is ON during a predetermined period of time. A second tracking module increments a second period of time when, during the predetermined period of time: (i) the HVAC system is ON and (ii) a split temperature of the HVAC system is outside of a temperature range of the HVAC system. A grade determination module determines a grade of the HVAC system for the predetermined period of time based on both the first period of time and the second period of time. A reporting module generates a displayable report for the HVAC system for the predetermined period of time. The report includes the grade of the HVAC system for the predetermined period of time.

Abstract: A vacuum appliance 10 with a display 24 to indicate status information relating to the vacuum or components thereof. For example, the display 24 may indicate the status of the vacuum appliance's 10 motor 12, airflow 16 and/or resulting suction, brush 20, container 22, or any combination thereof.

Abstract: A grading method includes: determining a first heat flux for a first period of a run cycle of a HVAC system of a building, wherein the HVAC system is in an OFF state during the first period of the run cycle; determining a second heat flux for a second period of the run cycle of the HVAC system, wherein the HVAC system is in an ON state during the second period of the run cycle; determining a third heat flux for the run cycle based on a sum of the first heat flux and the second heat flux; determining a power consumption of the HVAC system during the run cycle; determining a first grade for the HVAC system based on the third heat flux of the run cycle and the power consumption during the run cycle; and generating a displayable report, the report including the first grade of the HVAC system.

Abstract: A glass-to-metal hermetic seal assembly in a sight glass assembly or a hermetic terminal assembly is disclosed and includes a glass component, an intermediate component, and an outer ring. The intermediate component is provided around the glass component. The glass component is fused to the intermediate component. The outer ring, which has a coefficient of thermal expansion that is greater than a coefficient of thermal expansion of the glass component, compresses the intermediate component against the glass component to create a hermetic compression seal.

Abstract: An upright vacuum cleaner with one or more features, such as a top opening rigid container, a headlight, a replaceable power cord a motor housing suspended within the vacuum to reduce noise and/or vibration a clutch assembly with a RPM sensor, and/or one or more filter plates to improve airflow.