Abstract: A jewelry article is adapted for attachment as an extension of the temple arm on conventional eyeglasses. The jewelry extension, or "glasstension", grips the temple arm with an elastic loop portion of a gripping member, and the gripping member in turn supports one or more elongated strands of jewelry type decorations, such as beads and charms. Each glasstension is a unitary piece, with the elongated decorative strands being securely affixed onto the gripping member. In one particular embodiment, the glasstension includes two or more decorative strands, and two additional gripping members attached at or near the ends of two of the decorative strands, allowing the glasstension to be converted from a single sided glasstension to a combined double sided glasstension and eyeglass retainer.

Abstract: A jewelry article is adapted for attachment as an extension of the temple arm on conventional eyeglasses. The jewelery extension, or "glasstension", grips the temple arm with an elastic loop potion of a gripping member, and the gripping member in turn supports one or more elongated strands of jewelry type decorations, such as beads and charms. Each glasstension is a unitary piece, with the elongated decorative strands being securely affixed onto the gripping member.

Abstract: Backlighting for an LCD display is provided by a direct backlight unit which is hinged to the front panel in which the display is mounted. When closed, the backlight unit lamps and reflector transmit light directly against the back of the display. The reflector surfaces are made by a combination of constant radius, hyperbolic, parabolic and flat surfaces which maximize the emitted light transmitted to the display and help fill in for any failed or dimmed light sources.

Abstract: A method and apparatus to be used with a motor controller for determining if phase currents in a three phase AC motor are balanced. The phase angles between current zero crossing times for consecutive phase currents are compared to determine current balance and thyristor switches are employed to adjust phase angles and rebalance unbalanced currents.

Abstract: A digital communication network carries high and low priority data. The network stations that produce high priority data are assigned to a first group of stations and stations that produce low priority data are assigned to a second group with the two group not being mutually exclusive. Activity on the network is divided into periodic intervals of the same duration. Network control information, that defines how access to the medium, is determined is broadcast to all stations during a first segment of a periodic interval. The network control information defines the length of the periodic interval and of the periodic interval segments, and defines how many stations are in each group. Then during a second segment of the periodic interval, every station in the first group is afforded an opportunity, in a predefined order, to transmit high priority data over the medium.

Abstract: Activity on a digital communication network is divided into periodic intervals and during a segment of each periodic interval a moderator station broadcasts a numerical count of the periodic intervals to all stations on the network. Each station has a memory in which a numerical value is stored, and a comparator that compares the numerical value to the numerical count received from the network. When the numerical count of the periodic intervals equals the numerical value, an apparatus within the station performs a defined operation, such as transmitting a message over the network or synchronizing a clock in the station to a master time standard. The equality of the periodic interval count and the numerical value also can be used to determine when to signal an external device. By using the count of the periodic intervals in this manner, the operation of several stations on the network can be coordinated.

Abstract: An electric motor has three windings which are supplied by a three-phase source of electricity that has one polarity during a first half-cycle and another polarity during a second half-cycle. The motor is controlled by an apparatus that has three thyristor switches coupling the phases of the source to the motor windings. A switch controller triggers the thyristor switches to apply electricity that produces movement of the motor. One thyristor switch is operated to be in a first non-conductive state during a portion of every first half-cycle and in a second non-conductive state during a portion of every second half-cycle. The first non-conductive states are longer in duration than the second non-conductive states. A current sensor provides a first value that indicates the magnitude of the DC component of electric current flowing through one motor winding that is connected to the one switch.

Abstract: A node circuit is operative to couple Manchester encoded data between a transmission medium and an associated electrical device. A first mechanism detects a message frame preamble having a pattern of alternating signal level of substantially identical duration, and a second mechanism that detects a start delimiter in the message frame. The start delimiter has a plurality of binary signal levels in a unique pattern that satisfies a defined set of criteria to optimize the probability that the pattern will be detected while minimizing the likelihood that random valid data will alias into the start delimiter pattern. A data decoder is provided to convert the Manchester encoded data into binary data which then is sent via a signal path to the associated electrical device. Another mechanism is included to detect a unique end delimiter that signals the termination of the message frame.

Abstract: Activity on a digital communication network is divided into periodic intervals, that are further subdivided into first and second phases during which different classes of data are transmitted. A media access controller for a station on the network has an interface that connects to an external device which supplies first and second classes of data for transmission over the network. A first memory stores the first class of data and a second memory stores the second class of data. The external device supplies a third class of data that may be transmitted over the network during either the first or second phases. The third class of data is held in a third memory. A transmitter connects the three memories to the interface in order to send data over the network. A control circuit regulates the transfer of data from the memories to the transmitter, with data being transferred from the first memory when the media access controller has access to the network during one of the first phases.

Abstract: A motor controller for control of an AC motor which monitors the DC power provided to an inverter for synthesizing AC waveforms having the needed frequency and phase to power the motor. Information about variations in the DC power to the inverter are incorporated into the control strategy by adjusting a motor base frequency at which the motor moves from a constant torque to a constant horsepower mode of control. The change of control mode allows decrease in the field current, and hence a decrease in the required quadrature voltage while preserving the torque current. The torque current is ultimately limited by a user programmable direct voltage limit.

Abstract: A disk drive support system suspends a disk drive within a sleeve-like support housing from two upper corners and two lower corners using four parallelepiped shaped elastomeric mounts, one bridging the drive and housing at each corner. Each mount has one zone affixed to the drive and another opposite zone affixed to the housing by tangs on the drive and housing which engage two respective slots in the mount. A third slot is formed in the mount between the two zones so that there is no straight line path between the zones through the material of the mount which is not interrupted by the slot. The third slot thereby prevents transmission of direct compressive forces between the two zones, and thus requires at least some component of force acting between the two zones to act in shear. Shock absorber pads are provided on the disk drive which are separated from the housing by an air space so as to absorb shocks but not transmit vibrations.

Abstract: A communications protocol for use in implementing serial communications over a common system backplane in an industrial control system such as a remote I/O system. The protocol includes separate start access, read access and write access sequences. Different locations at which I/O modules may be present as defined by select line connections are polled pursuant to the start access sequence to verify the presence of such modules. Module status words and separate groups of data read words and data write words are exchanged over the system backplane in standardized data frames. As the data bits of the data words are transmitted they are echoed back to the transmitting component for error detection purposes.

Abstract: Each message carried by a communication network has a packet that contains data, a tag, and a generation count wherein duplicate packets sent in different messages have identical generation counts. A station includes a modem that connects to the communication network in order to receive messages. A fixed screener circuit has a first memory that stores a set of tag values and a fixed screener determines when a packet tag matches a tag value in the first memory. The station also has an interface through which tag values are received from an external device, such as a host computer. A general purpose screener includes a second memory with a plurality of storage locations in which to store tag values from the interface and a generation count associated with each tag value.

Abstract: A control system for controlling the temperature within process machinery such as the feed assembly in an injection molding machine. The control system provides a six phase process for starting up the machine from cold conditions and controlling the machine temperature to rapidly and accurately attain a command temperature while identifying control parameters for use under steady state conditions for maintaining the command temperature.

Abstract: A real time three-phase analyzer stores digitized values of the signals of the three-phase circuits in memory so that they may be addressed according to circuit and sample number. Positive, negative and zero phase sequences are developed without the need for trigonometric calculation by combining samples offset in memory by a number of samples approximating 120.degree.. That number of samples may be determined for an arbitrary frequency of the three-phase system by identifying zero-crossing points of one such signal and assuming the number of samples equates to 360.degree. of phase of that circuit. The phase sequence of the three circuits necessary for the calculation of the positive, negative and zero phase sequences may be determined by comparing the relative position of positive going zero-crossings for each of the three circuits.

Abstract: A fuse blown detection circuit for use in conjunction with the control transistor output circuits of a programmable controller which provides low leakage after the fuse is blown. The detection circuit comprises a pair of voltage dividers and a diagnostic triggering device forming an H-bridge network connected across the terminals of the fuse and a blocking diode. When the fuse is blown the voltage levels defined by the dividers change to activate the trigger device and enable a diagnostic signal indicative of the fuse blown condition while the blocking diode prevents current flow back through the control transistor and output circuit.

Abstract: An operator interface for a photoelectric control unit including a graphical display having a plurality of icons corresponding to different control functions and a numerical display for indicating parameter settings and operating margin values. The operator interface allows the user to rapidly and conveniently reconfigure the control unit for operation in a number of different modes in accordance with a number of different operational settings. Furthermore, the interface provides information on the operating margin of the photoelectric control unit which can be useful to the operator in aligning the unit and in judging conditions under which the unit is operating. Furthermore, the operator interface allows the user to select different light pulse repetition rates and corresponding operating ranges for the photoelectric control unit.