Abstract: A clock line over-protection circuit (28) carried on an interface card (16) for interfacing synchronous clock line (20), power line (22), DC common line (24) and data line (26) between a host computer (12) and a plurality of data link modules (14) with a plurality of associated controlled devices (18) including a series resistor (52) interconnected between a clock disable switch (52) and a clock signal generating amplifier (48) and a current sensor circuit (64, FIG. 3) connected across the series resistor (50) to produce a current sensor signal on an output (62). The current sensor signal is integrated by an over-current protection circuit (58, FIG. 4) to produce an over-current detection signal that varies with the difference in the clock line current magnitude during clock signal phases of opposite polarity.

Abstract: A communications network has an operator interface system for monitoring and controlling controllers utilizing any known control strategy. A common database is accessible across the communication network of controllers regardless of each controllers dissimilar data structure. The operator interface provides an apparatus for displaying, storing, and editing data obtained from the network. Data from each controller can be accessed by a master device based upon the controller's individual data structure and type through embedded objects resident in the master device's operating system and program. The data can then be displayed, edited, and stored by any data entry device that is capable of executing the master's program.

Abstract: A phase control system has a stable timebase phase reference generated by an internal phase reference generator which has improved transient response in the presence of spurious noise generated by other external equipment coupled to the same voltage source. A digital phase comparator estimates a phase error between the timebase phase reference and the voltage source. The internal phase reference generator constructs the timebase using a normalized difference between the volt-time-areas between two adjacent quadrants of the internal timebase phase reference. This allows corrections to the phase reference generator to be made on the next cycle of the phase reference generator based on the error estimate of the present cycle.

Abstract: A programmable data link module for use with a time division multiplex data bus includes an input and a high voltage protection circuit to prevent outputting of data to the data bus under several different operation conditions. These include programming of the data link module and verification of the programming. The data link module also inhibits the outputting of data signals to the data bus in response to changes of the input signals from a local input device until the power to the data link module has stabilized for a preselected period of time. The high voltage protection circuit protects the data link module from excessive overvoltage from other devices connected to the data bus.

Abstract: A weld controller is coupled to a communications network which has an operator interface unit for monitoring and controlling the weld controller and other weld controllers on the network. A time of day clock provides a chronological reference to tag weld current and voltage data and other data when it occurs for storage in its memory which is also accessible by the operator interface unit for storing in said system database. A memo pad in the weld controller is also accessible to the network for storing data for diagnostic purposes, said data including faults, events, and other operational data. The data can then be displayed, edited, and stored by the operator interface's program.

Abstract: A weld control system, supplied by a polyphase voltage source, consists of an isolation contactor supplying power to separate single phase weld controllers. The single phase weld control systems have their separate power modules combined into a single power module assembly for more efficient cooling and electrical interfacing. The single power module consists of a semiconductor switch for each phase of the polyphase voltage source and a single chiller plate for mounting and cooling the switches. The chiller plate functions as a heat sink and is machined to create a series of channels that become coupled together to form a continuous tube having a single input and a single output for a coolant liquid. A SCR pair, housed in a single package in a back-to-back configuration having an isolated base construction. The base has good thermal conductivity between the heat generating semiconductors in the package and the base.

Abstract: A programmable data link module is used on a time division multiplex data bus. The module receives data from the data bus during a selected time slot for a selected number of frames. The data link module includes an input circuit for generating a data output signal data to the data bus in response to input signals from an input device coupled to the module. The input circuit includes a data bus integrity checker for determining whether the data bus is intact. A test signal is sent by a master clock source to the data link module and if it is properly received, the integrity checker will permit the data link module to received data signals from the data bus.

Abstract: A weld controller is coupled to a communications network which has an operator interface unit for monitoring and controlling the weld controller and other weld controllers on the network. A common database in the operator interface unit is accessible across the communication network by the weld controller regardless of the data structure of the database. The weld controller can use the database to obtain different weld schedules, duplicate its own weld schedule to provide for easy replacement, and as a data storage for its operating parameters and values. The weld controller has a dual communications port that allows for a variety of operator interface configurations. Data from weld controller can be accessed by the operator interface controller based upon the weld controller's individual data structure and type through embedded objects resident in the operator interface's operating system and program.

Abstract: A communication system between a programmable logic controller and a network of a plurality of remote input/output repeater modules uses a synchronous serial communications protocol. The programmable logic controller contains a transmitter module for generating a data packet containing the state of an output device connected to a remote input/output repeater module coupled to the network. A receiver module receives and decodes a returned modified data packet that indicates the state of input devices connected to the same or other remote input/output repeater modules also coupled to the network. The remote input/output repeater modules receive and decode the data packet to determine the state of the output devices that may be connected to it and modifies the data packet to indicate the state of its input device if there is one present. The modified data packet is sent to the next in-line remote input/output repeater module coupled to the network.

Abstract: A process of manufacturing an insulator having a central core and an insulating body fitted tightly around the central core includes interposing a flexible coating layer between a part of the central core and the insulating body. The flexible coating layer fills in shrinkage cavities and compensates for a retraction effect caused by injected material used in forming the insulating body. The insulating body is achieved by overmolding the central core previously coated with the flexible coating layer with an injected insulating resin such as a thermoplastic or thermosetting resin. The insulator could be used as a capacitive divider or bushing insulator.

Abstract: A programmable data link module (32) for use in a time division multiplexing control system (30) having a plurality of modules interconnected by a bus (40) for passing control signals between data link modules on a serial multiplex basis. Each module includes an integrated circuit (80) having signal conditioning circuits (180, 186 and 188) including a programmable hysteresis circuit (126), a power on reset delay circuit (190), a safety input inhibit circuit (220), a clock loss detect circuit (240), a safety output protection circuit (262), a data verifier (260), a polarity selector for a third output terminal (350), an input synchronizer (182 and 184), a combined mode/sync output terminal (110), a multiplex clock output terminal (108), a programming circuit (232) for accepting programming over the clock bus (44) and data bus (46), input/output word extender circuits (104, 106), a high voltage protection circuit (420) including a transistor (600) and a data bus integrity checker (630).

Abstract: A weld control system, supplied by a polyphase voltage source, consists of multiple and separate single phase weld controllers. The single phase weld control systems have their separate power modules combined into a single power module assembly for more efficient cooling and electrical interfacing. The single power module consists of a semiconductor switch for each phase of the polyphase voltage source and a single chiller plate for mounting and cooling the switches. The chiller plate functions as a heat sink and is machined to create a series of channels that become coupled together to form a continuous tube having a single input and a single output for a coolant liquid. A SCR pair, housed in a single package in a back-to-back configuration having an isolated base construction. The base has good thermal conductivity between the heat generating semiconductors in the package and the base.

Abstract: A programmable data link module is used on a time division multiplex data bus and includes a system master clock signal. The module is functional as an input device, an output device, or both as an input and output device. It receives data from the data bus during a selected time slot for a selected number of frames to control output devices connected to it. The data link module includes a clock loss signal for generating an inhibit signal when a loss of the master clock signal is detected. The inhibit signal will prevent any changes to the state of the output device during the duration of the loss of the master clock signal.

Abstract: A programmable data link module is used on a time division multiplex data bus having a repetitive time frame, each time frame having a plurality of time slots. The module receives data from the data bus during a selected time slot for a selected number of frames. The data link module includes a data verifier for storing the received data during the selected frames and inhibits outputting of data signals to the data bus until a repetitive occurrence of the received data over the selected number of frames has been verified.

Abstract: A programmable data link module for use with a time division multiplex data bus includes a word extender module. The module can receive, send, or receive and send data over the data bus during a preselectable time period. The time period is defined by a programmable starting address and an ending address. The data can be single or multibit and variable length as determined by the time period selected.

Abstract: A networked control system includes graphical representations of actual devices coupled to a network. The graphical representations include symbols that provide an actual picture of the devices and means for displaying values and status of the devices. A controller uses a system database to create an application database that is used for controlling and monitoring the devices. The system database and application database combine to form a real-time distributed database for controlling devices on the network. The system database includes templates for the physical devices with a control structure that has prelinked parameters that relate to the representation. A graphic editor allows a user to create the database from templates in the system database. Data and other device parameters are automatically linked to a device symbol when creating the graphical representations. A process controller couples the devices to the network and provides the data and status of the networked device to the system.

Abstract: A networked control system includes graphical representations of actual devices coupled to a network. The graphical representations include symbols that provide an actual picture of the devices and means for displaying values and status of the devices. A controller uses a system database to create an application database that is used for controlling and monitoring the devices. The system database includes templates for the physical devices with a control structure that has prelinked parameters that relate to the representation. A graphic editor allows a user to create the database from templates in the system database. Data and other device parameters are automatically linked to a device symbol when creating the graphical representations. A process controller couples the devices to the network and provides the data and status of the networked device to the system database.

Abstract: A non-ferrous current sensor is used to continuously measure the charging current magnitude in step-graded foil and paper insulation systems and capacitive insulation systems used on high voltage measurement and control apparatus such as instrument transformers and on the condenser bushings of power transformers and circuit breakers. The low voltage measured signal is conditioned by an electronic circuit that modulates a DC signal in a system current control loop to provide continuous remote monitoring and alarm functions. Remote power is supplied to the sensor and conversion circuits through the current loop. The sensor detects changes in the charging current through the insulation ground conductor, indicating the degradation of the dielectric properties between the foil layers. The sensor and associated electronic circuitry are enclosed in a housing adaptable to be used with a capacitance tap common to high voltage measurement and control apparatus.

Abstract: A multipurpose golf tool having an unique construction that makes it easy to incorporate multiple features and functions within a single, rigid and generally flat body section that fits in the palm of the golfer hand yet can be stored in a pocket without causing damage to the clothing.