Abstract: A series resonant circuit converts a DC input to an AC output. The circuit includes first and second series circuits connected across the DC input, but in opposite polarities. Each series circuit includes a switch, a transformer primary and a capacitor. Also within each series circuit, a diode is connected across the combination of the switch and transformer primary to provide limiting. The transformer primaries are connected together so that the switches are effectively in series. Singular and multiple transformer cores may be used in connection with singular and multiple secondaries to provide the AC output.

Abstract: A circuit used to convert a DC input to an AC output includes a pair of series circuits. Each of the series circuits is in parallel with the DC input and includes a switch and a transformer primary. A capacitor couples the two series circuits, and is attached to each series circuit at a node between the respective transformer primary and switch. A secondary on the transformer provides the AC output. Optionally, multiple transformers may be utilized. Similar topologies may be used for rectification instead of inversion.

Abstract: A field mountable controller boots by transmitting a seed letterbug to a server. The server responds with an initial operating system and program. The program reads configuration information about the controller and transmits it back to the server which responds with a particular letterbug for the controller. The controller then transmits the letterbug to a boot image server which returns a corresponding operating system image to the controller. The controller then boots using the operating system.

Abstract: A solenoid actuated valve has a magnetic armature slidably received in a closed guide member secured to the valve body by a spin welded ring. The armature guide has external peripheral teeth which interengage corresponding internal teeth on the solenoid coil assembly to permit any desired rotational orientation of the coil when assembled onto the guide. The coil assembly is secured in the desired rotational position by interengagement of the teeth and is secured axially by snap tabs formed on the end of the guide.

Abstract: In a process control system, a user selects a displayed object. The user then asks to be shown documents related to the selected object. A list of related documents is automatically displayed to the user who may then select a document for display. The association of documents with displayed process control objects is facilitated by a document librarian. Within the document librarian, a user drags documents from within a document hierarchy over to hierarchically designated objects within the process control system, and drops them thereon. Links between the documents and the process control objects are thereby established.

Abstract: An I/O device powered by its computer interface is interfaced to a computer through a PC Card. A dongle is included with a cable assembly between the PC Card and the I/O device. Power for the I/O device is supplied thereto by an external power supply connected to the dongle. Using a power status input, the PC card can detect whether the external power supply is operational and connected, and accordingly, the PC Card manages operations with the I/O device.

Abstract: A PCMCIA card includes a processor and a dual-ported memory thereon. The PCMCIA card is plugged into a host, such that both the PCMCIA card's processor and the host have access to the dual-ported memory. Upon initialization, the host will load the dual-ported memory will a boot sequence for the processor on the PCMCIA card. The processor on the PCMCIA card is then released from a reset state, and proceeds to boot from the boot sequence loaded by the host. The processor on the PCMCIA card is released from reset by the host accessing a predetermined location within the address space of the PCMCIA card.

Abstract: A power converter circuit emulates the functioning of the satuarable reactor therein using a solid state switch in connection with a control circuit. The power converter circuit includes a voltage source and an output. A switch having a control input and current carrying terminals couples the voltage source to the output. An integrator is connected across the current carrying terminals of the switch. A current source is coupled to the integrator. A comparator couples an output of the integrator to the control input of the switch. The comparator turns on the switch when said output of said integrator exceeds a threshold voltage.

Abstract: A PC Card includes a printed wiring board with an edge-card connector formed integral therewith. Wiring of the printed wiring board connects the edge-card connector to components on the printed wiring board. Connection is established to the printed wiring board via the edge-card connection for testing and programming of components on the PC Card.

Abstract: A brushless DC motor is controlled by determining a speed of the motor and a line voltage supplying drivers of the motor. Based upon these determined values and predetermined motor performance data, a maximum PWM on-time is determined for drive signals supplied to windings of the motor. This maximum PWM on-time thereby limits motor torque output to a predetermined maximum. Stopping the motor is performed in sequential phases including a loaded generator phase, an active braking phase and a holding phase. During holding, the amount of energy supplied to the motor is reduced to the point just before slippage such that holding energy is minimized. Upon power failure, the motor is driven toward a spring return home position overcoming static friction that may prevent the spring return mechanism from functioning properly. These techniques are applied to a motor in an actuator.

Abstract: A brushless DC motor is controlled by determining a speed of the motor and a line voltage supplying drivers of the motor. Based upon these determined values and predetermined motor performance data, a maximum PWM on-time is determined for drive signals supplied to windings of the motor. This maximum PWM on-time thereby limits motor torque output to a predetermined maximum. Stopping the motor is performed in sequential phases including a loaded generator phase, an active braking phase and a holding phase. During holding, the amount of energy supplied to the motor is reduced to the point just before slippage such that holding energy is minimized. Upon power failure, the motor is driven toward a spring return home position overcoming static friction that may prevent the spring return mechanism from functioning properly. These techniques are applied to a motor in an actuator.

Abstract: A brushless DC motor is controlled by determining a speed of the motor and a line voltage supplying drivers of the motor. Based upon these determined values and predetermined motor performance data, a maximum PWM on-time is determined for drive signals supplied to windings of the motor. This maximum PWM on-time thereby limits motor torque output to a predetermined maximum. Stopping the motor is performed in sequential phases including a loaded generator phase, an active braking phase and a holding phase. During holding, the amount of energy supplied to the motor is reduced to the point just before slippage such that holding energy is minimized. Upon power failure, the motor is driven toward a spring return home position overcoming static friction that may prevent the spring return mechanism from functioning properly. These techniques are applied to a motor in an actuator.

Abstract: A planar array of electric conductors is stamped from a sheet of conductive material and has tabs for each of the conductors bent outwardly of the plane of the material. The conductors are interconnected by a plurality of webs and are affixed to a dielectric carrier sheet by an adhesive, whereupon the webs are severed and the conductors have electrical isolation. The carrier sheet and conductors are attached to a control panel and electric control devices are attached to the control panel over the conductors. The control devices are provided with terminals that extend in the same direction as the tabs of the conductors, and the control devices are electrically connected to the conductors by double ended push-on preformed connectors.

Abstract: An electronic selector knob circuit (10) which uses a tapped potentiometer (POT1) to provide accurate operation without requiring factory calibration. The potentiometer (POT1) is calibrated through on-board circuitry which includes a tap voltage biasing device and which monitors operation on a continual basis through both a current monitor (16) and a voltage monitor (18). A redundant disable circuit (14) provides a redundant hardware means for shutting off all oven heating elements.

Abstract: A multi-wavelength optical filter for a portabe gas analyzer includes a filter assembly having a first opening and multiple additional openings. The first opening has a linearly variable filter disposed therein, while the additional openings have discrete filters disposed therein. The filters are linearly aligned, such that filter selection is facilitated by using the filter assembly with a linear positioning mechanism.

Abstract: A wet scrubber control system is configured with a pH sensor and a conductivity sensor in the return solution, and with a conductivity sensor in the feed solution. Concentration of the scrubbing agent within the feed solution is determined using the conductivity of the feed solution, corrected by subtracting a bias therefrom. The bias is established by first measuring the concentration of scrubbing agent in the return solution using the pH sensor. An expected conductivity of the return solution is then looked-up. The bias is set as the difference between the expected conductivity of the return solution and a measured conductivity of the return solution.

Abstract: A power conditioning circuit for use in a power supply includes a power input and a power output. The circuit also includes a series connected RFI-EMI filter, rectifier, and SCR between the power input and the power output. The SCR has a control input for switching the SCR on and off, thereby interrupting current flow between the power input and the power output. An energy storage circuit is connected across the power output. Furthermore, the circuit includes a control circuit coupled to the control input of the SCR for switching the SCR on and off to maintain a regulated voltage at said power output in response to an AC input. A conditioned DC output is produced in response to a DC input.

Abstract: A method and apparatus for training and optimizing a neural network for use in controlling multivariable nonlinear processes. The neural network can be used as a controller generating manipulated variables for directly controlling the process or as part of a controller structure generating predicted process outputs. The neural network is trained and optimized off-line with historical values of the process inputs, outputs, and their rates of change. The determination of the manipulated variables or the predicted process outputs are based on an optimum prediction time which represents the effective response time of the process output to the setpoint such that the greatest change to the process output occurs as a result of a small change made to its paired manipulated variable.