Abstract: A microphone acoustical polar pattern converter conveniently converts the acoustical polar pattern of a microphone from cardioid to supercardioid and back at will. The converter includes primarily a body of a tubular body portion fitted forward of the microphone head. Most preferably, the body is formed of open pore plastic, with a pore size of 70 microns.

Abstract: A three-dimensional ultrasonic position control device suitable for controlling computer displays or robot movements is disclosed.More specifically, signals from an ultrasonic transmitter are received by multiple receivers. The received signals are processed by a processing circuit which provides signals to a computer system for use in controlling a computer display or a robot. This system is particularly adapted to use inexpensive components to provide for a low cost mass producible control device.

Abstract: In a vehicle presence detection system in which an inductive sensor loop is the frequency-determining element of the tuned circuit of a loop oscillator, discrimination against variations in inductance due to environmental changes is achieved by comparing detect and tracking reference numbers with a sample number that is a function of the oscillator frequency and updating each reference number repeatedly at real time intervals independent of loop oscillator frequency. The current sample number is compared with either the tracking reference or the detect reference according to whether or not the system is indicating the presence of a vehicle.

Abstract: An ergonomically-shaped hand controller of the type commonly referred to as a "mouse", is specially configured to prevent or reduce hand muscle fatigue despite continuous use over a protracted period of time. A housing for receiving the anterior surface of the hand comprises an arched metacarpalphalangeal support surface, distal phalange support surfaces for the volar pads of the thumb and forefinger and a medial ledge for supporting the remaining three ulnar fingers in a partially wrapped configuration with flexion of the distal, middle and proximal phalanges.

Abstract: A fault diagnostic apparatus for a device subject to a plurality of predetermined fault conditions. The apparatus includes a fault detector for automatically detecting the occurrence of any of the plurality of fault conditions and an indicating circuit for indicating the occurence of only specific one of the plurality of fault conditions manually designated by an operator.

Abstract: A relative position indication system comprises a cyclical position sensor which includes first and second plates having cyclical windings thereon. The position indication system is operative for determining the relative cycle position between the windings on the first plate and the windings on the second plate within a single cycle and for determining a cycle count representing the number of whole cycles by which the first and second plates have been repositioned relative to each other. The position indication system is further operative for combining the relative cycle positions with the cycle count in order to determine the overall relative position of the plates, and it is operative for updating the cycle count without updating the relative cycle position each time the plates are aligned in a zero or initialized position.

Abstract: A single link digital telemetry system transmits data in serial form from a sending station. The data clock signal is recovered at a receiving station for data synchronization purposes. To achieve recovery of the data clock signal the incoming data is synchronized with a high frequency clock of n times the original data clock frequency; the fast clock is utilized to drive a data latch so that on each positive incoming data edge the latch produces a synchronized data pulse for feeding to a recirculating shift register n bits long, which is also driven by the fast clock. The original data pulse can be recovered merely by tapping off from a chosen location on the register.

Abstract: The duration of time during which an AC power voltage sinusoidal waveform remains between negative voltage threshold -V1 volts, nominally 5% of negative peak voltage -V2 volts, and positive voltage threshold +V1 volts, nominally 5% of peak positive voltage +V2 volts, is detected. By the change in voltage with time exhibited by a sinusoidal waveform in the region of zero voltage crossing, the expected time duration between voltage thresholds in approximately 5% of one-half period of such sinusoidal waveform. If the actual time between voltage thresholds exceeds (nominally) twice this value, or 10% of one-half period, then a power black-out condition is sensed, and a power fault signal is produced.

Abstract: An apparatus for retracting a microphone is provided and consists of a microphone holder affixed to a free end of a retractable chain from a spool within a housing whereby when an operator needs to transmit, the microphone is pulled away from the housing. When transmission is completed the chain will go back into the housing around the spool place the microphone back against the housing where it is safe from damage and out of the way. Modifications of the spool is provided to allow for different lengths of chain to be wrapped around the spool.

Abstract: A plurality of terminal units are connected to the central unit by one optical fiber line in a loop form, thereby forming a communication link. The central unit converts the data including the terminal address and control bit into the serial optical signal and outputs this optical signal. The terminal unit receives and interpretes the optical signal from the central unit and ON/OFF controls the solenoid valve. After completion of the control, the terminal unit rewrites the control bit in the reception data to the data bit indicative of the operating state of the valve and transmits the data bit to the next terminal unit. The central unit receives the signal from the final terminal unit and interprets the bit data which was rewritten from the control bit by the terminal unit, thereby displaying the operating state of the valve.

Abstract: A keyboard having a series of parallel bars capable of mechanical displacement by downward thrust under the pressure of the user's fingers, and a luminous display system in which a tactile electric control screen forms the top of the bars. Circuits are used for producing control orders from at least bar data and key data, with the bar data being selected according to the bars depressed. Specific key functions are assigned electronically to screen zones disposed at intervals along each bar, and a controller provides the display system with a visual representation related to each key function in the corresponding screen zone.

Abstract: A data input device having key switches which are temporarily in an operated position, and position-hold switches each having selectable stable positions. The device includes a first matrix, a second matrix, and a matrix scanning arrangement. The first matrix comprises first and second signal lines which cross each other, and the second matrix comprises third and fourth signal lines which cross each other. Each key switch is connected between the first and second lines at a corresponding one of the intersections. Similarly, each position-hold switch is connected between the third and fourth lines at a corresponding one of the intersections. Some of the first or second lines are used as the third or fourth lines.

Abstract: A capacitive linear or rotary transmitter for controlling and positioning displaced objects by measuring the displacement, angle or speed of the displaced object is formed, in one embodiment as a rotary transmitter, by two mutually opposed stators defining a reciprocal spacing, their gap having rotatably arranged in it a rotor which is rotatably coupled to a spindle which is coupled to the displaced object. Capacitive values varying during the rotation of the rotor may be measured in the air gaps produced in each case between one stator and the rotor, and the other stator and the rotor. To attain a superior degree of precision and resolution, coatings are so arranged on the rotor and the stators, as to produce at least two concentric annular areas, of which one area forms the measurement track of a coarse measuring system and the other area forms the measurement track of a precision measuring system.

Abstract: An improved system for generating a signal representative of the level of a material having a dielectric constant within a vessel is disclosed. The system features use of a first probe for generating a signal indicative of the dielectric constant of the material which is divided into a signal varying with the level of the material whereby a compensated level signal irrespective of the actual dielectric constant is measured. In a preferred embodiment, a single integrator is used to perform the division operation whereby inaccuracies due to component variation including long-term drift are eliminated. The instrument is disclosed as functioning in a two-wire instrument system having low power requirements, permitting use of conventional signal limits.

Abstract: A two-wire, admittance-responsive instrument system in which a transmitter, receiver and calibrator are connected by a two-wire transmission line is disclosed. The calibrator repetitively transmits a calibration enabling signal causing the transmitter to increment a reference admittance for comparison to a sensed admittance corresponding to a known physical condition. The calibrator monitors the bistable output signals transmitted by the transmitter in the calibration mode, which changes state when the incremented reference admittance bears a predetermined relationship to the sensed admittance. The calibrator may then transmit additional calibration enabling signals causing preload to be established for transmitter operation.

Abstract: When a key is inserted into a key hole of a lock, magnetism creating means creates a magnetic flux corresponding to a predetermined magnetic code set in the key. Magnetism detecting means detects the magnetic flux and outputs a signal representing the detected magnetic flux. Decision means compares the signal value with a predetermined value, and outputs an agreement signal when the two values are the same. Driving means enables at least unlocking by key operation in response to the agreement signal. The magnetism detecting means outputs, as the above signal, a voltage corresponding to the magnitude of the detected magnetic flux or pulses having a frequency corresponding to same. At least one of material, dimensions, and thickness of the magnetic element determines the predetermined magnetic code. Further, an unlocking mechanism has a magnetic actuator which unlocks the lock by coupling the lock with unlocking means via a cam in response to the agreement signal.

Abstract: A frequency-hopping radio communication system is disclosed comprising a control unit which transmits to and receives from each of a plurality of slave stations using a frequency-hopping mode of operation. During a start-up mode, the control unit communicates a starting message to each slave station using a predefined frequency. The message identifies to each slave station a frequency-hopping sequence to be used to select the frequencies from a group of frequencies for transmission to and reception from the control unit. This message also specifies to each slave station unique starting frequencies in the frequency-hopping sequence at which to begin transmitting and receiving. All slave station transmissions are synchronized to the control unit transmissions, thereby preventing any two stations from concurrently using the same frequencies for either transmitting to or receiving from the control unit.

Abstract: In prior cellular radio transmission systems a base radio station (BS) periodically transmits references identifying control channels associated with such base radio station, references identifying control channels of adjoining base stations, and references identifying a substitute control channel. The invention reduces the number of references which must be transmitted by a base station, which is of particular advantage in an integrated services cellular radio transmission system. A transmission channel of each base station is assigned as a simplex message transmission channel (COCH) in which a given base station (BS) transmits to the mobile stations (MS) information describing the structure of the control channels (CCH). Such information includes references (NC) to message transmission channels of adjoining base stations and references (CC) to one or more control channels assigned to the given base station.

Abstract: A telemetry system for use with implantable medical devices is disclosed which utilizes both in-phase and quadrature data components, and frequency modulates both data components into a single transmitted sinusoidal signal which varies in frequency between two selected frequencies. The signal is received and decoded, preferably by a coherent decoder, into in-phase and quadrature components, which are then integrated and sampled to produce the two transmitted in-phase and quadrature data components, which may then be recombined to produce the transmitted data. The system requires only low power, and is capable of operating at a relatively high data rate while retaining a high degree of accuracy due to the splitting of the signal into the in-phase and quadrature data components.

Abstract: A retrofit, automatic audit system for a door-access, coin-operated newspaper rack machine is disclosed. The system operates in conjunction with the standard door-lock mechanism and includes a retrofit purchase-mechanism mounted on the machine. The purchase-mechanism includes an electromechanical audit structure which is operatively connected to the purchase-mechanism and door-lock mechanism and monitors and records service and transaction audit data involving the purchase-mechanism. A portable data transfer unit is proximity coupleable with the audit structure for acquiring audit data therefrom. The system includes proximity activation through magnetic structure which causes the audit structure to shift from a data acquisition mode to an automatic data transfer mode when a data transfer unit is proximity coupled thereto. Communication means between the audit structure and the data transfer unit includes an optical structure providing communication therebetween.