Abstract: A piezoelectric transformer has pairs of input/output electrodes located on a piezoelectric body corresponding to period locations on a standing sine wave superimposed on said body, and having a waveform corresponding to vibrational modes of the piezoelectric body at resonance. The transformer also has a grounded guard electrodes to reduce parasitic coupling between its input and output regions.

Abstract: A self-trimming current source for used in a switched current source DAC is made from a fixed current source and a variable current source, which are connected in parallel to provide a total output current. The total output current is automatically calibrated by temporarily switching one side of the self-trimming current source to a measurement circuit. Based on the measured value, the variable current source is adjusted to make the total output current equal to a predetermined value. The fixed current source is implemented with a complementary pair of field-effect transistors (FETs) connected in a cascode connection, with the two drain terminals presenting high impedances to the circuitry to which they are connected. A DAC typically includes a plurality of self-trimming current sources, each of which is calibrated during each DAC conversion cycle.

Abstract: A parasitically powered remote sensing device for monitoring an industrial system. The device comprising a tuned transducer which converts stray energy emitted by the system into an electric potential for consumption by a remote sensing device and/or a wireless communications link. In an alternate embodiment the remote sensing device further comprises an energy storage element connected to the transducer to provide the sensing element and wireless communications link with the electric potential when the stray energy is insufficient to power the remote sensing device.

Abstract: Reversible electrochemical mirror (REM) devices typically comprise a conductive oxide mirror electrode that is substantially transparent to radiation of some wavelengths, a counter electrode that may also be substantially transparent, and an electrolyte that contains ions of an electrodepositable metal. A voltage applied between the two electrodes causes electrodeposition of a mirror deposit on the mirror electrode and dissolution of the mirror deposit on the counter electrode, and these processes are reversed when the polarity of the applied voltage is changed. Such REM devices provide precise control over the reflection and transmission of radiation and can be used for a variety of applications, including smart windows and automatically adjusting automotive mirrors. According to the present invention, measurements of the sheet resistance of the mirror electrode in a REM device are correlated with the thickness of electrodeposited mirror metal and can be used to monitor the reflectance of the device.

Abstract: A transparent, refracting material is disposed atop an opto-electronic substrate device. Such refracting material has formed therein a plurality of microlenses arranged in a regular, tessellated pattern, which is superimposable on a regular tiling pattern of polygonal cells, attached to one another at defining polygonal borders. The contours of the refractive microlens' surface have rotational symmetry within each cell about an axis, with the symmetric contour maintaining its symmetry substantially at every surface point within the cell's borders. The microlens surface is fabricated by printing a contour into a photoresist using grey scale photolithography, then transferring the contour into an underlying refractive planarizing material, suitably by ion etching. The method produces a microlens array in which each microlens maintains its symmetric contour substantially across a polygonal cell, thus achieving almost unity fill factor without significant aberrations.

Abstract: A programmable analog I/O circuit for use in an industrial control system has a first mode of operation as an input circuit and a second mode of operation as an output circuit. In the first mode of operation, a device-side I/O terminal is adapted for receiving an analog input status signal from an analog input device. In the second mode of operation, the device-side I/O terminal is adapted for transmitting an analog output control signal to an analog output device. According to another aspect, a programmable I/O circuit that drives an output device in an industrial control system comprises a plurality of configurable gain stages and a plurality of programmable isolating links. The plurality of programmable isolating links are coupled to the plurality of configurable gain stages and are programmable to determine a series or parallel arrangement of the plurality of configurable gain stages.

Abstract: Insulating slot liners for insertion into stator core winding slots are formed from a narrow-width reel of insulating material. The width of the material is determined by the inner circumferential surface of the winding slot that must be insulated, instead of being based on the axial length of the stator core as has been the practice in the past. As a result, slot liners may be easily produced for stator cores of different axial lengths by simply adjusting the length of material cut from the reel. Preferably, the cutting mechanism used to cut the length of material is adapted to form a pair of opposed cuffs when the material is cut. An insulator blank formed in this manner is pushed into a die, thereby forming a U-shaped slot liner. A transfer mechanism functions to move the slot liner into a respective winding slot. The slot liner preferably passes through a reduced diameter guideway defined in a guide element as it is moved into the winding slot.

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 human/machine interface for designing, monitoring and troubleshooting complex industrial control systems uses the paradigm of the factory floor to organize machines, control program portions and data as virtual spatially linked objects that may be moved in three dimensions to be joined with other spatially linked objects. The user may move within the virtual factory floor among the spatially linked objects followed by spatially indifferent objects which provide tools for monitoring and interacting with the spatially linked objects. Proximity of visual objects determines data sharing between objects.

Abstract: PLZT piezoelectric ceramics having the general formula (Pb1−xLax)(ZryTi1−y)1−(x/4)−zMa+4z/a O3 are fabricated in a hot forging process using PbO, TiO2, ZrO2, and La2O3 powders with Nb2O5 and Ta2O5 added to provide 2.0-3.0% Nb5+ (mole %) and 2.0-3.0% Ta+5 (mole %) as a dopant. ZrO2 and TiO2 powders are mixed at a molar ratio of y/(1−y), the preferred molar ratio being 55/45, calcined at approximately 1300° C.-1500° C., ball milled in acetone, and evaporated to a dry powder. The mixture of ZrO2 and TiO2 is then combined with PbO2, La2O3, Nb2O5 and Ta2O5 powders, and the new mixture is ball milled in acetone, evaporated to a dry powder, calcined at approximately 700°-850° C., and sifted to obtain a particle size of approximately 0.5-1.5 &mgr;m. The final Nb/Ta-doped PLZT powder is formed into the desired shape by cold pressing followed by sintering at approximately 1000° C.-1150° C. in oxygen.

Abstract: Multiple bits of information may be conveyed by passive target material incorporating filaments of magnetizable material having different magnetization functions and, in particular, different coercivities. Detection of the presence or absence of the individual filaments may be done remotely by measuring induced flux B as a function of an externally imposed magnetic field waveform and subjecting the measured induced flux signal to differentiation or Fourier transform techniques.

Abstract: A method and apparatus for automatically selecting and employing different DC link pre-charge levels dependent upon different sources providing power to a power conditioning system wherein the different sources are characterized by different source inductances, the apparatus including a source control that selects a first pre-charge level when a utility supply provides power to the system and selects a relatively lower pre-charge level when a generator supply provides power to the system thereby reducing the possibility of inverter disablement due to DC link voltage dips.

Abstract: A connector and cable system for panel mounted circuitry includes two-piece connectors designed to receive flat cabling including both power and data conductors. The connectors are designed to be snapped into apertures of a support panel, such as in a component enclosure. The flat cabling extends between base and cover portions of the connectors. Insulation-piercing conductors within the base portion of the connectors complete electrical contact with conductors within the cable and provide an interface for component cabling, such as a multi-pin socket. The cable assembly may be fabricated on the support panel and the entire assembly added to the enclosure for final assembly.

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 include data indicating not only their constraints of operation but also reflecting the constraints of operation of machines to which they are attached and with which they share common operating parameters. An autonomous controller associated with a machine having operating parameters in common with another machine adopts the intersection of the ranges of the machine constraint of the two machines. Machine constraints are preserved to the extent possible as ranges so as to permit flexibility in selecting and seeking goals by the individual autonomous control units.

Abstract: A table of sequential call statements is used to organize various program portions of the operating system of an industrial controller. This organizing structure allows troubleshooting of individual program portions of the operating system as are intimately related to the controlled process and the control hardware on an individual basis without the need to generate dummy programs or “stubs” to replace the unexecuted program portions. Those program portions not being executed have their call instructions replaced by NOP instructions. The call table may be edited to provide for different operating modes of the industrial controller without the need for mode test flags otherwise dispersed within the program code of the operating system.

Abstract: High data rate I/O modules may be placed on a synchronous bus used also with legacy low data rate I/O modules without rendering the latter modules incompatible and without changing the clock rate of the bus by interleaving extended data to be read at falling edges of the clock with conventional data for the legacy modules to be read at rising edges of the clock. High data rate modules read both extended and conventional data effectively doubling the data transmission rate.

Abstract: The drive for an a.c. induction motor features a rectifier for converting alternating current into direct current and a current source inverter for converting direct current into alternating current supplied to a motor. A d.c. link choke interconnects the rectifier and the inverter. The inverter includes a first control loop which provides a desired or command d.c. link choke current to a second control loop responsible for the rectifier. For the purposes of the second control loop the actual d.c. link choke current and an input voltage of the inverter are detected. The difference or error between the desired and actual d.c. choke currents are minimized by a compensator. The output of the compensator is added to the detected inverter input voltage, and the sum is fed to a switching pattern generator which controls the switches in the rectifier. In this manner the feedback of the inverter input voltage is decoupled from the compensator responsible for the d.c. link choke current.

Abstract: An inverter circuit includes a pair of switching devices coupled in series across high and low sides of a direct current bus. An output line is coupled between the devices for conducting controlled alternating current power produced by timed switching of the devices. A flyback diode is electrically coupled a in parallel with each switching device and is physically positioned adjacent to the opposite switching device in the pair. Conducting paths between each diode and the associated switching device are preferably physically positioned adjacent to conducting paths between the switching devices and the output line. The placement of the elements cancels or reduces parasitic inductance during switching. Three similar arrangements may be provided in parallel in a three phase inverter. The inverter may be incorporated into a power substrate including a rectifying circuit for converting alternating current power to direct current power to be applied to the bus.