Abstract: A current sensor includes a deflectable member disposed in a magnetic field. Nulling or compensating members may be mechanically coupled to the deflectable member. Feedback or readout devices coupled to the structure provide signals indicative of deflection of the deflectable member under the influence of applied current and the magnetic field. Nulling current applied to the nulling members tends to oppose deflection of the deflectable member. The nulling current may be modulated to drive the feedback signal to a desired level and is used as a basis for calculating the current to be measured. The current may be measured directly upon calibration of feedback devices coupled to the deflectable member or to the nulling members. Arrays of sensors may be coupled to common busses for applying measured and nulling currents to sensors of the arrays and for detecting feedback signals.

Abstract: An electromechanical device comprises a stator and a rotor which is capable of rotating relative to the stator. The rotor has a sensor embedded therein. In a preferred embodiment, the sensor is disposed within a plurality of laminations that are stacked one on top of another. For example, one of the plurality of laminations may be a sensor lamination, in which case the sensor is at least partially disposed within a cavity formed in the sensor lamination. Advantageously, the sensor may be used to directly measure rotor-associated operating conditions, such as rotor current (including the magnitude, frequency and phase of the rotor current), rotor fatigue, rotor temperature, rotor airgap, rotor flux and rotor torque. The sensor is especially well-suited for measuring current in the rotor of an induction motor.

Abstract: A system for controlling contrast of a liquid crystal display is provided by means of a parallel network of resistors. A processor controls general operations of the system and is configured to determine a desired contrast setting of the LCD. The processor is operative to assign a binary value corresponding to the desired contrast setting. A binary decoder is operatively coupled to the processor and is configured to receive the binary value of x bits from the processor. A circuit includes N number of resistors (N being an integer greater than x) configured to be coupled in parallel to effect a plurality of cumulative parallel resistance values for the circuit. The circuit is operatively coupled to the binary decoder. The binary decoder selectively combines the resistors to effect a specific cumulative parallel resistance value corresponding to the desired contrast setting.

Abstract: A capacitance comparison circuit determines the relative value of two capacitors, such as may be sensor elements, by monitoring voltage changes caused by charge redistribution between the capacitors when they are series connected and then connected alternately in a first and second polarity across a voltage. The direction of change of voltage at the junction of the capacitors with respect to the switching of polarity of their connection precisely reveals which capacitor is larger. Disconnecting the voltage monitor during the switching reduces switching induced errors.

Abstract: An electromagnetic operator includes first and second coils wound coaxially. An armature partially surrounds the coils for channeling flux during energization of the coils. The armature may be formed of a bent plate and secured to a ferromagnetic support. A control circuit applies energizing signals to the coils during operation. Both coils are energized during an initial phase of operation. One of the coils is subsequently released or de-energized automatically. A timing circuit removes current from the second coil after a variable time period. The time period may be a function of the configuration of the timing circuit, such as an RC time constant, and of the energizing signal.

Abstract: A technique for supplying power and data signals to panel-mounted components includes distribution of power and data conductors in a trunk wireway and further distribution to component locations via drop cable assemblies disposed in drop wireways. The drop cable assemblies and trunk cable assemblies may include identical cable. The cables have a plurality of parallel conductors in an insulated jacket. Connectors are mounted on the drop cable assemblies for receiving plug-in component cable assemblies routed to individual components mounted within component panels or bays. The components are thus electrically coupled in parallel with one another and may receive both power and data signals via the drop and trunk cable assemblies coupled to a network. Individual components may be independent installed and removed for servicing with interrupting service to upstream or downstream components in the system.

Abstract: An operating system for distributed industrial controllers ensures the completion of enrolled application programs within a predetermined time span as is required for robust industrial control by preallocating dynamic and static hardware resources on a per application basis and in a manner that ensures execution of the application within the necessary time constraints. Portions of the distributed operating system may be distributed at particular hardware resources to provide necessary modeling for those hardware resources in making the commitments to resource bandwidths.

Abstract: Circuitry for protecting a first electrical system when connected to a second electrical system via a bus which provides a current-carrying signal to the first electrical system and includes a reset signal which is monitored by the second electrical system. The circuitry includes a capacitor connected to the current-carrying signal of the bus. A first switch is electrically connected between a node of the capacitor and a ground point. The first switch is closed when the first electrical system is powered-up and open when the first electrical system is powered down. A second switch is electrically connected between the reset signal of the bus and the ground point. The second switch closes due to the energy accumulated by the capacitor when the first switch is open.

Abstract: A broadband test procedure detects the onset of stator winding insulation damage, identifies the failure mechanism, determines the winding's susceptibility to further damage, and predicts stator winding failure. This is accomplished by realizing that changes in the stator winding insulation and/or geometry are reflected as changes in the capacitance between the individual windings and, hence, as changes in the stator winding's broadband impedance response. In the currently preferred approach, the impedance response includes the frequency, magnitude, width, and phase of the resonant impedance.

Abstract: A contact assembly comprising a plurality of pairs of spaced apart fixed contacts supported in an electrically insulating body, an actuator displaceable relative to the body between first and second positions, and a plurality of movable contacts mounted on the actuator. Each movable contact is positioned on the actuator so as to interconnect the contacts of one of the pairs of fixed contacts only when the actuator is in one of the first and second positions. Each fixed contact has two limbs defining an L-shape, one limb defining a single leg which extends through an aperture formed in a partition defined by the body and the other limb extending to one side of the leg to define a head supporting a terminal for gripping a wire. Each movable contact is displaceable into contact with the leg of each of the respective pairs of fixed contacts on the side of the leg from which the head extends and on the side of the partition remote from the head.

Abstract: A method and apparatus for reducing distortion at the outputs of an inverter system, the apparatus including a polarity discriminator for determining the polarity of a current passing through an output terminal to a load, a compensator programmed with different upper and lower compensation values and controlled by the discriminator to provide the upper compensation value as an output when the current polarity is positive and providing the lower compensation value when the polarity is negative and a combiner for receiving a modulating signal and the compensation value provided by the compensator and mathematically combining the two signals to generate a modified modulating signal.

Abstract: A development tool for control programs for industrial controllers develops an area-model detailing equipment and phases of operation of the equipment of a controlled process. This area-model is used as a framework for integrating reusable program fragments together into a cohesive control program. The area-model provides a naming convention for otherwise conflicting variables of the reused control components that preserves the identity of the control variables for subsequent programming. The renaming convention may be tracked so that other program portions stored together with the control program fragments in a library of object templates may be interconnected through the same or other editing systems.

Abstract: A networked system combines multiple workstations, storage devices and file handlers with multiple computer numerical controls. Typically, each workstation comprises a personal computer with a Windows-based operating system utilizing a standard process-to-process communication protocol, such as Dynamic Data Exchange (DDE). This type of system allows a wide variety of M-to-N topologies in CNC environments. Further, the use of a file management system, according to the present invention, allows the activation and execution of part program operations at a computer numerical control on files accessed through standard open networks.

Abstract: A method for mitigating current distortion on inverter supply lines that supply a load with power from a PWM inverter, the inverter including a switch and diode bridge constructed using devices that are characterized by losses that cause current distortion, the invert, lines and load together characterized by inductive and capacitive dynamics that also cause line current distortions, the method including identifying both a device drop error due to device operating characteristics and a system related dynamics error due to interaction of system components and using those errors along with a more conventional dead time compensation scheme to modify modulating waveforms used in PWM comparison by a controller.

Abstract: A current sensor includes a deflectable member disposed in a magnetic field. Nulling or compensating members may be mechanically coupled to the deflectable member. Feedback or readout devices coupled to the structure provide signals indicative of deflection of the deflectable member under the influence of applied current and the magnetic field. Nulling current applied to the nulling members tends to oppose deflection of the deflectable member. The nulling current may be modulated to drive the feedback signal to a desired level and is used as a basis for calculating the current to be measured. The current may be measured directly upon calibration of feedback devices coupled to the deflectable member or to the nulling members. Arrays of sensors may be coupled to common busses for applying measured and nulling currents to sensors of the arrays and for detecting feedback signals.

Abstract: An electronic device/heat sink assembly having at least first and second heat generating electronic devices, a heat sink member, a resilient integral spring clip, the clip including a base member and first and second oppositely facing resilient leg members extending from opposite ends of the base member, the heat sink member having oppositely facing first and second surfaces, a separate one of the electronic devices positioned on each of the first and second sink surfaces, the clip dimensioned and positioned such that the leg members sandwich the devices and heat sink therebetween.

Abstract: An interface for a network communication card for industrial controllers uses a dual-port memory that may be re-partitioned by values communicated through the dual-port memory itself. A default partitioning and a non re-partitionable common area allow flexible re-partitioning without disrupting the communication necessary for the partition to take place. Negotiation between the controller and network card allow maximum flexibility in re-partitioning while respecting partitioning limits characteristic of the network card and its network.

Abstract: A highly reliable industrial controller uses low complexity field programmable gate-arrays (FPGA) in lieu of standard microprocessors where each FPGA is programmed so as to provide for a different internal implementation of the control program as a set of interconnected logical gates. Variations in the outputs of the FPGAs caused by hardware failure may be corrected by choosing the most common output, a default output or a default value. Errors may be detected though conventional hardware error detection methods or by a direct comparison of the outputs which under normal conditions should match each other.

Abstract: An industrial control system uses a number of autonomous control units, each associated with one piece of equipment in an industrial process. The autonomous control units negotiate by bidding among themselves to determine a common set of input and output values for the interconnected machines with which they are associated. Each autonomous control unit determines whether input values are acceptable by using a model of its associated equipment. The model provides anticipated output values which may be compared against a predetermined range of outputs of associated machines, outputs compatible with downstream machines, or the constraints of the overall industrial process according to a designated job to be accomplished. Optimization of the input and output values is provided by allowing preliminary bids to be the subject of optimizing counter-bids if the original bid value could have been accepted.

Abstract: A system and method is provided for selecting a test load and/or bias resistor utilized in an expandable load system employing a backup power source. The test load and/or bias resistor is selected based on the actual load present in the expandable system. The backup power source is periodically tested during normal operation of the expandable load system utilizing the test load. A test load is provided that is sized for the actual load of a local load under worse case conditions. If an expansion load is connected to the local load the test load is adjusted, so that the test load is based on the actual load of the local load and the expansion load. Additionally, a bias resistance can be provided for driving a switch that allows power to be provided to the local load during power loss mode. If an expansion load is connected to the local load, the bias resistance is adjusted to correspond to a bias resistance necessary to provide the current for the actual load of the local load and the expansion load.