Abstract: The load current drawn from a power transformer is sensed to determine if and when the load current exceeds a predetermined threshold. The length of time the load current exceeds the threshold is also sensed. By monitoring the excess current flow and the length of time for which it flows, it is possible to anticipate a rise in the winding temperature of the power transformer and to initiate cooling before the windings have reached a critical temperature, as a function of the ambient temperature and/or the temperature of the transformer. Thus, systems embodying the invention include circuitry for sensing the current drawn from and/or by a transformer, determining when the current exceeds a predetermined value and timing circuits for sensing the length of time for which the excess current flows. The timing circuits are needed, in part, to differentiate between a transitory overload condition and a static, continuous, overload condition.

Abstract: Multi-layered cards embodying the invention include a buffer layer between a PET layer and a PVC layer. The buffer layer is selected to have temperature and stress responsive properties intermediate to those of the PET and PVC layers. The buffer layer is formed of a material which has a low degree of moisture absorbance whereby the surface of the PVC layer is protected from moisture in the atmosphere. The buffer layer is also more elastic than the PVC layer.

Abstract: A matrix array of photo elements (pixels) arranged in rows and columns with at least one row conductor per row of the matrix and a column conductor per column of the matrix for selectively the pixels. Each pixel of the matrix array includes: (a) a photodetector for detecting light pulses incident on the pixel and producing an output signal indicative of an incident light pulse; (b) signal processing circuitry coupled to the photodetector and responsive to its output signal for generating an electrical pulse corresponding to each incident light pulse; and (c) counting circuitry coupled to the signal processing circuitry for storing information indicative of the number of light pulses incident on the photodector during a sensing period. Row and column decoders are respectively coupled to the row and column conductors of the matrix array for reading out the contents of the array a row at time and for resetting the pixels of each row after their contents have been read out.

Abstract: Apparatus for shaping a selected end region and the opening at a selected end of a hollow cylindrical glass tube includes a support member for holding and rotating the tube in a controlled manner and a heat source for supplying sufficient heat to the selected end region of the tube to place it in a malleable state. The apparatus also includes an actuatable mechanical holding means for holding a multi piece mold and for selectively applying the mold to the selected end region of the tube, when the tube is rendered malleable, for shaping the selected end region of the tube including its rim and for controlling the inner diameter of the tube throughout its end region. In one embodiment the apparatus includes a temperature sensor for controlling the operation of the mechanical holding means and the action of the heat source and a micro-controller for automatically activating the application and retraction of the mold.

Abstract: A mold for shaping the end region and the opening at a selected end of a first, hollow, generally cylindrical, glass tube to enable a second tube, of smaller diameter than the first tube, to be inserted snuggly a first distance within the selected end of the first tube resulting in the two tubes nesting and being self-centered. The mold includes two complementary elongated side pieces having inner side surfaces for, when joined, encircling the periphery of the first tube along a given portion of its selected end region, and an end cap with a cylindrical stub for insertion within the opening of the first tube at its selected end.

Abstract: A transducer operated as power generating device is driven at a low frequency and collects energy at the low frequency rate. The collected energy is extracted at a much higher frequency. Extracting the energy at a higher frequency enables the use of components, such as inductors, having reasonable values and sizes. In one embodiment, a power extracting circuit which includes elements designed to resonate with the transducer at a higher frequency than the frequency at which the transducer is being driven is periodically switched in circuit with the transducer. Thus, the electric power generator device operated and controlled by a slowly changing source of energy (e.g., ocean waves, wind, eddies of water) may develop energy at one frequency and may be operated to transfer the energy at another frequency.

Abstract: Systems and circuits embodying the invention include means for sensing at least one of the peaks, amplitude and frequency of an oscillatory input force impinging on a power generating device for controlling the turn-on of a switch used to transfer energy collected by the power generating device to an associated load. The power generator may be a transducer such as a piezoelectric device or a wave energy converter (WEC). Sensors and sensing means embodying the invention are used to control the point in time at which power extracting circuits are switched in circuit with the power generating device. The power extracting circuit may include components which can resonate with the power generating circuit at a higher frequency than, and independent of, the frequency at which the power generating device is being operated. Thus, an electric power generator device operated and controlled by a slowly changing source of energy (e.g.

Abstract: Subranging techniques using “digital SQUIDs” are used to design systems with large dynamic range, high resolution and large bandwidth. Analog-to-digital converters (ADCs) embodying the invention include a first SQUID based “coarse” resolution circuit and a second SQUID based “fine” resolution circuit to convert an analog input signal into “coarse” and “fine” digital signals for subsequent processing. In one embodiment, an ADC includes circuitry for supplying an analog input signal to an input coil having at least a first inductive section and a second inductive section. A first superconducting quantum interference device (SQUID) is coupled to the first inductive section and a second SQUID is coupled to the second inductive section.

Abstract: In accordance with the invention, a single sideband mixer includes first and second all-pass 90° phase shifters. Each phase shifter produces two outputs of substantially equal amplitude but subject to a phase angle error (&thgr;) indicative of a deviation from quadrature of the two outputs. The phase angle errors of the first and second phase shifters are designed to be equal and to track each other over different ambient and operating voltage conditions. In one embodiment, the outputs of the first phase shifter are coupled via a cross switch to the inputs of two mixers and the outputs of the second phase shifter are fixedly connected to the inputs of the two mixers. The outputs of the two mixers are combined to produce an output whose frequency is a function of either the sum or the difference of first and second input frequency signals respectively applied to the first and second phase shifters.

Abstract: A circuit includes at least one odor-sensitive organic field effect transistor (OFET) having a conduction channel whose conductivity changes in response to certain ambient odors and a feedback loop coupled between an output and an input of the circuit. The feedback loop generates a feedback signal which stabilizes the output signal of the circuit for time drift of the odor-sensitive organic transistor. In one embodiment, the OFET is an integral part of an amplifier and generates input signals to the amplifier in response to certain odors. A selectively enabled switch may be coupled between the output and the input of the amplifier circuit to provide negative feedback that tends to cancel the effect on the amplifier of time drift due to the OFET.

Abstract: In accordance with the invention, a preform from which fiber optics are drawn is fabricated by supplying reactants and gas vapors to the preform and by using two opposing forces to control the movement of a heat source supplying heat to the preform. The two forces function to reduce any hesitation or backlash in the movement of the heat source along predetermined portions of the preform to enable uniform layers to be formed within the preform.

Abstract: In systems embodying the invention, a “downed” power line is detected by sensing whether there is an open circuit along the power line and producing an indication that an open circuit condition exists. In response to an indication that an open circuit condition exists, the system compares the nature of the voltage and/or current signals present on the power line at the time an open circuit condition is indicated to exist, with a preprogrammed stored condition which includes typical signals to be expected when a “break” occurs along a power line. When a downed power line is detected, power is then removed from the affected line.

Abstract: A frequency detector embodying the invention includes circuitry for comparing first (e.g., a reference) and second (e.g., a recovery clock) signals having first and second frequencies, respectively, and for producing an output signal having: (a) a first condition characterized as a “dead zone” when their frequency difference is within a predetermined frequency range; (b) a second condition when the frequency of the first signal is greater than that of the second signal by the predetermined range; and (c) a third condition when the frequency of the second signal is greater than that of the first by the predetermined range. Frequency detectors embodying the invention are suitable for use in frequency tuning systems.

Abstract: An electrical energy generator relying upon piezoelectricity includes electrical generating elements comprising electroded bodies of an electrostrictive material, e.g., polyurethane, having inherent but weak piezoelectric characteristics. A d.c. bias is applied between the electrodes for field-inducing a larger piezoelectric characteristic whereby, upon applying mechanical energy to the element, in known manner, for alternately straining and destraining the body, electrical charge is generated on the electrodes with a high mechanical energy to electrical energy conversion efficiency.

Abstract: A method of securing a mounting bracket on a wall of a structural member comprises inserting lugs of the mounting bracket through slots through a wall of the member and securing the lugs to an inside surface of the wall. The mounting bracket is used for mounting the structural member within a cabinet by sliding the member in snug fit within a cabinet, the internal securing of the lugs avoiding interference with the snug fitting relationship.

Abstract: Apparatus embodying the invention includes first and second motors coupled to a carriage assembly for moving the carriage assembly back and forth between first and second end points. The first motor is for developing a force to drive the carriage in one direction and the second motor is for developing a force to drive the carriage in an opposite, second direction. When the first motor causes the movement of the carriage in one direction, the slowing, stopping and reversal of the carriage is achieved by varying the power supplied to the second motor relative to the power supplied to the first motor until the force exerted by the second motor first equals and then exceeds the force exerted by the second motor. So operated, the carriage motion is well controlled and exhibits little, if any, backlash.

Abstract: A capacitance multiplier network embodying the invention includes a first resistor, R1, connected between a first node and an intermediate node and a first capacitor, C1, connected between the intermediate node and a point of reference potential. A unity gain amplifier has an input connected to the intermediate node and its output is connected via a second resistor, R2, to the first node. The unity gain amplifier ensures that the voltage drop across the second resistor is equal to the voltage drop across the first resistor. The effective capacitance, Ce, of the network is equal to C1 times [R1+R2]/R2. Thus, by making R1 larger than R2, Ce is much large than the capacitance of C1. The capacitance multiplier network is well suited for use in phase locked loop circuits and enables the integration of a very dense circuit on the same IC chip.

Abstract: An optical pattern reading apparatus includes a housing with a light projecting means located within the housing for projecting a line of light onto an optical pattern located external to the housing and wherein the line of light is cyclically swept across an optical pattern to be read. A reflecting mirror located in the housing, posteriorly of the light source is moved in synchronism with the line of light projected onto the optical pattern to receive a line of light reflected from the optical pattern and projecting its reflected light via a light receiving and condensing optics assembly onto a linear image sensor. The information present within an area can thus be sensed using a linear image sensor.

Abstract: One aspect of the invention is directed to on-chip high-frequency, low-jitter clock circuits including long Josephson junction (LJJ) oscillators usable as clock sources. LJJ oscillators embodying the invention may be formed using either “linear” or “annular” long Josephson junctions. This invention enables the generation and distribution of a stable high-frequency on-chip single flux quantum (SFQ) clock. The on-chip clock circuit may include a clock selector circuit and a clock distribution scheme and may be integrated with RSFQ circuits and/or with a wideband analog-to-digital converter (ADC) comparator. The invention also includes a new fluxon “sender” circuit suitable for synchronizing the LJJ oscillator with another oscillator, either on-chip or external to the chip. The new sender circuit may also enable the realization of a novel phase-locked loop (PLL) circuit.

Abstract: In systems embodying the invention a voltage responsive circuit is used to generate a number of different clock signals having the same frequency, with each clock signal being delayed relative to any other clock signal by a certain delay which is a function of the amplitude of a control voltage applied to the voltage responsive circuit. The clock signals are multiplexed to enable any one of the different clock signals to be selected and to then be compared with a reference frequency signal for producing a gradually varying control voltage which is applied to the voltage responsive circuit. The different clock signals are suited for use in applications such as clock recovery and frequency synthesizer systems, where very little jitter is desired.