Abstract: A movable contact assembly for contactors and similar devices includes a movable spanner or conductive element biased toward a conducting position by a biasing element. A housing partially surrounds the conductive element and the biasing element. The biasing element and exerts compressive forces against the housing and the conductive element. The assembly may be installed as a modular unit on a carrier which is displaced during operation of the contactor. The housing shields the biasing element from plasma, arcs and debris during operation of the device. Multiple conductive elements and corresponding biasing elements may be includes in each assembly.

Abstract: A method is provided for sensing and measuring an electrical current. The current to be measured is applied to a deflectable member in a sensing module in the presence of a magnetic field. Deflection of the member is detected as an indication of the current. A nulling current may be applied to one or more additional deflectable members mechanically linked to the deflectable member. Feedback or readout signals indicative of deflection of the members are monitored. The nulling current is modulated to drive the feedback signals to a desired level. The nulling current value is converted to a value representative of the current to be measured.

Abstract: In a method of measuring a current, the current is received at a winding and permitted to flow through the winding, which is wound about a core. The flow of the current through the winding induces a first magnetic flux that flows through the core and that tends to drive the core into saturation. The core is actively reset to prevent the core from being saturated at least during selected time intervals. The current is then measured during at least a plurality of the selected time intervals. In a particularly preferred embodiment, the winding is a primary winding and the resetting step includes applying a reset voltage to a secondary winding using a source that is coupled to the secondary winding. The reset voltage determines a rate at which a net magnetic flux that flows in the core changes in a direction away from saturation. Advantageously, the current sensing method has a tremendous dynamic range.

Abstract: A network system is provided for transmitting electrical power and data signals between a plurality of device nodes. The system includes a trunk cable in which a pair of dedicated power conductors and a pair of dedicated signal conductors are embedded in an insulative cover. Modular connectors are electrically coupled to the cable conductors at each device node. Each connector includes a base module and an interface module. The base module is attached to the cable via insulation piercing members and thereafter remains resident on the cable. The interface module is mated with the base module and serves to transmit power and data signals between the base module and a networked device. Several types of interface modules may be utilized interchangeably to permit the base module and cable to accommodate various types of devices and device drop cables.

Abstract: A simple voltage window sensing circuit including a current indicator, two Zener diodes and two digital transistors wherein the diode breakdown voltages are selected such that they define the upper and lower voltage limits of a voltage window, each diode causing a corresponding transistor to conduct when the breakdown voltage is exceeded, the indicator in series with a first transistor which is controlled by the diode which defines the lower limit and the transistors in parallel such that the first transistor only conducts when a voltage is within the window and hence the indicator only indicates when the voltage is within the window.

Abstract: A system of interlocking modules for use with a programmable logic controller. The system utilizes a plurality of modules, e.g. input/output modules, that are mechanically interlinked to obviate the need for a rack or back plane. Each module includes a movable plug portion that selectively may be moved into engagement with a corresponding plug receptacle of the next adjacent module. The mechanical interlocking features and the plug portions are designed to permit insertion and removal of individual modules disposed between adjacent modules, without moving either of the adjacent modules.

Abstract: A method and apparatus for determining the absolute position of a rotor in a permanent magnet synchronous machine (e.g. motor or generator) at standstill wherein short positive and negative voltage pulses are separately provided to each stator winding and the rate of current change with respect to time for each current is determined, the rates are used to determine general rotor position angle and thereafter are used to determine correction angle for correcting the general angle.

Abstract: A programmable controller includes memory for storing a ladder logic control program having a plurality of ladder logic instruction rungs. Each rung begins with a start of rung (SOR) instruction. A processor is coupled to the memory for executing the ladder logic control program. User interrupts are disabled during execution of the rungs. During execution of the SOR instruction, a predetermined register, such as a MCR register, is read causing simultaneous enabling of user interrupts which overrides the previously disabled user interrupts to allow the processor to receive an interrupt request signal. The interrupt request signal is received before the read function of the predetermined register has completed.

Abstract: High aspect ratio filaments of magnetic material are randomly dispersed in a non-magnetic matrix such as paper or plastic for part of a critical component of a manufactured product to permit remote sensing of the manufactured product by the application of an external oscillating magnetic field and the detection of the resulting induced magnetization. The material may be incorporated into a wide variety of products that must be remotely sensed.

Abstract: A mobile human machine interface for a monitoring operation of a spatially distributed control system in a factory or the like provides a location signal to a central processor holding the control program and relevant I/O data. Based on that location signal, the mobile HMI receives data relevant to the machines near its location. As the user moves through the factory, its location signal changes and the data and program which it executes changes accordingly. The user may identify him or herself to the mobile HMI providing for a second degree of discrimination in the type of data provided to the mobile HMI.

Abstract: A multi-motor drive in which the resonance existing between one or more output filter capacitors of a current source inverter and an a.c. induction motor is reduced. The inverter features a switching pattern generator which controls the power switches of the inverter based on a reference current. A control loop, connected to the switching pattern generator, measures the load current or voltage and generates a nominal reference current based on an error therein; determines a damping current based on the voltage at the terminal; and determines the reference current supplied to the switching pattern generator by subtracting the damping current from the nominal reference current. The invention essentially simulates the use of a physical damping resistor connected in parallel with each output filter capacitor, but without the corresponding energy loss.

Abstract: An electrochemical mirror includes a transparent first electrode and a second electrode. An electrolytic solution, disposed between the first and second electrodes, contains ions of a metal which can electrodeposit on the electrodes. A negative electrical potential applied to the first electrode causes deposited metal to be dissolved from the second electrode into the electrolytic solution and to be electrodeposited from the solution onto the first electrode, thereby affecting the reflectivity of the mirror for electromagnetic radiation. A surface modification layer applied to the first electrode ensures that the electrodeposit is substantially uniform, resulting in a mirror layer which increases the reflectivity of the mirror. A positive electrical potential applied to the first electrode causes deposited metal to be dissolved from the first electrode and electrodeposited from the solution onto the second electrode, thereby decreasing the reflectivity of the mirror.

Abstract: A system software solution for controlling an enterprise which defines and illustrates the electrical, pneumatic, hydraulic, logic, diagnostics, external behavior, controlled resources and safety elements of an enterprise control system. The elements of the control system are encapsulated in objects of an object-oriented framework within a control assembly. The control assembly is the fundamental building block for providing object-oriented control of the enterprise. A control assembly component is a deployable control subsystem that provides an interface using a common object model that is configurable. The enterprise control system includes facilities for retrieving external models utilizing a predefined interface. The retrieved model includes support for external resources such as an external resource tree in which the leaf nodes correspond to resources to be controlled, resource and process information and a computer aided design model.

Abstract: The present invention relates to a fabrication process relating to a fabrication process for manufacture of micro-electromechanical (MEM) devices such as cantilever supported beams. This fabrication process requires only two lithographic masking steps and offers moveable electromechanical devices with high electrical isolation. A preferred embodiment of the process uses electrically insulating glass substrate as the carrier substrate and single crystal silicon as the MEM component material. The process further includes deposition of an optional layer of insulating material such as silicon dioxide on top of a layer of doped silicon grown on a silicon substrate. The silicon dioxide is epoxy bonded to the glass substrate to create a silicon--silicon dioxide-epoxy-glass structure. The silicon is patterned using anisotropic plasma dry etching techniques.

Abstract: A multi-phase vacuum contactor occupying a minimal space envelope. The contactor features a housing; a carriage; an electromagnetic actuator fixed to the housing and having a reciprocating armature connected to the carriage; and a plurality of vacuum interrupters each having a reciprocating stem for the actuation thereof, wherein the vacuum interrupters are fixed to the housing and circumferencially arranged about the electromagnetic actuating mechanism such that longitudinal axes of the vacuum interrupters are substantially parallel to a longitudinal axis of the electromagnetic actuating mechanism, and wherein the stem of each vacuum interrupter is connected to the carriage.

Abstract: A system software solution for controlling an enterprise which defines and illustrates the electrical, pneumatic, hydraulic, logic, diagnostics, external behavior, controlled resources and safety elements of an enterprise control system. The elements of the control system are encapsulated in objects of an object-oriented framework within a control assembly. The control assembly is the fundamental building block for providing object-oriented control of the enterprise. A control assembly component is a deployable control subsystem that provides an interface using a common object model that is configurable. The enterprise control system is used to define user interfaces including sequence charts that are updated in a substantially realtime manner utilizing the control assemblies associated with the generated code for the enterprise control system.

Abstract: A programming language for programming industrial controllers in relay ladder logic language, the programming language including both extensions to standard RLL rung form itself and extensions wholly independent of the standard form. The language uses a plurality of templates, each template including truly reusable relay ladder language sections. Most templates also include specifications identifying other templates which provide additional language logic required to define job-specific aspects of the referencing template. Using the templates a machine tree can be provided which mirrors an industrial process. By compiling all of the templates, a relay ladder language program can be provided.

Abstract: Low voltage logic circuitry is used to permit an entire subsystem of an industrial controller to be placed within a hazardous environment to receive a high speed serial link and undertake the control of multiple control points without expensive and awkward long cable runs and electrically isolating circuits for each cable run. Energy and bandwidth limiting on the high speed link allows power levels commensurate with high data rates yet intrinsic safety of the media allowing it to freely pass in and out of the hazardous area. A mixture of intrinsically safe and non-intrinsically safe equipment on the same logical rack is allowed through a bus isolator providing isolated data communication in backplane fashion between modules while wholly isolating power transmission along the backplane.

Abstract: A method and apparatus for minimizing resonant oscillations in a dual inertia system characterized by minimally stable poles and both a resonant frequency and an anti-resonant frequency, the apparatus including a notch filter which is tuned so that notch filter zeros essentially cancel the minimally stable poles and so that at least one notch pole is located at the intersection of a real axis and an system anti-resonant zero radius on a root-loci plot, thereby rendering an exceptionally stable system, the method for tuning the notch filter as described.

Abstract: Graphically intense utility programs for an industrial control system, requiring the same operating system as is used to run the control program, are run on remote computers having insufficient memory or processing power to support the operating system, by using a shell program executing on a control-computer to run the utilities. The shell program uses the control-computer's operating system except for calls to the remote computer's display or its manual input devices which are routed to a virtual machine updated periodically by communication with the remote machine.