Abstract: Audioconference system for conference connecting a plurality of groups of remotely located conferees, which comprises a loudspeaker assembly and a plurality of microphones respectively assigned to the conferees and grouped in pairs of microphones diametrically opposite with respect to the loudspeaker assembly. The output signals of the first microphones of the pairs are directly connected to a mixing circuit whereas the second microphones of the pairs are connected to this mixing circuit through a 180.degree. phase shifter. The signal components originating from the loudspeaker assembly and picked up by the microphones due to acoustical coupling between the loudspeaker assembly and the microphones are thus cancelled. Further the addresses of the conferees who are talking are derived from the detected voice signals and this detection is made through a pass-band filter.

Abstract: A condition control system utilizing a digital display arrangement is disclosed. The system provides for a digital input of the setpoint of the system, and a digital display to display the setpoint selected for the system. The system also measures the controlled condition and provides a digital display of the output. The system provides further that when the controlled condition is within a predetermined or preselected range of the setpoint condition, that the digital display is caused to display the setpoint value even though it may be slightly different than the actual sensed value.

Abstract: A digital programmable timing device to control the acquisition of data by a computer from high response probes in periodic flows. Synchronized sampling of probe measurements uses a phase-locked-loop and counting circuits so that the moment of A/D conversion always corresponds to a programmable displacement of a stationary probe with respect to moving rotor blades independent of RPM. The rotor speed also is measured digitally in one revolution of the rotor shaft.

Abstract: A speech analyzer for recognizing an unknown utterance as one of a set of reference words is adapted to generate a feature signal set for each utterance of every reference word. At least one template signal is produced for each reference word which template signal is representative of a group of feature signal sets. Responsive to a feature signal set formed from the unknown utterance and each reference word template signal, a signal representative of the similarity between the unknown utterance and the template signal is generated. A plurality of similarity signals for each reference word is selected and a signal corresponding to the average of said selected similarity signals is formed. The average similarity signals are compared to identify the unknown utterance as the most similar reference word.

Abstract: A distortion sound effects circuit producing an output signal corresponding to an input signal but containing one of four selected types of distortion. A compressor which includes a voltage-controlled amplifier first compresses the audio input signal within preselected limits, and the distortion operations are performed on the compressed audio signal to advantageously render the subsequent distortion operations insensitive to gross amplitude fluctuations of the input signal. The compressor includes means for full-wave rectifying the compressed audio signal. The full-wave rectified signal is provided as a distorted output signal containing hard-even distortion of the type commonly achieved by severely, asymmetrically clipping a signal. A distortion circuit includes single voltage controlled square-low amplifier to which the compressed audio signal is applied performs the other three types of distortion.

Abstract: A thermocouple linearizer circuit for use in a device for digitally displaying the temperature of a thermocouple. The circuit includes a plurality of proportional correction means, each connected to receive a non-linear electrical signal representing the temperature of a thermocouple. The correction circuits generate a correction signal proportional to the difference between a non-linear electrical signal and a predetermined reference signal. The correction signals are initiated when the non-linear signal exceeds the respective reference signal in each correction circuit. An arithmetic unit is included for adding the correction signals and the non-linear signal thereby forming a signal corresponding to a linear function of the temperature of the thermocouple.

Abstract: A digital-to-analog converter circuit suitable for implementation as an integrated circuit in integrated-injection-logic form, and a method for regulating the collector current in a plurality of integrated-injection-logic transistors are disclosed. A plurality of switching transistors are connected to digital input terminals and the currents conducted by the plurality of switching transistors are summed to yield an analog output current. An injection bar shared by each of the switching transistors provides drive current to the plurality of switching transistors. The injection bar is also shared by one or more reference transistors, the current in which is determined by a current source. A feedback circuit is used to regulate the bias of the common injection bar such that the current conducted by each switching device corresponds to the current conducted by each reference device.

Abstract: Apparatus for detecting a peak value of an analog signal includes a first counter for counting pulses from a digital clock for successive samplings of the analog signal to convert each sample of the analog signal into digital form and a counting register into which the pulse count in the first counter is transferred to be recounted at a later sampling. With a prior digital count in the register, the digital clock simultaneously (1) increments the counter to count the current signal sampling and (2) decrements the register to zero to recount the prior signal sampling. The counter is constrained to count up until both counting and recounting steps are complete before the count in the counter is transferred to the register. In this manner the counter will always attain the greater of the current and the prior sampling pulse count values and this maximum value will always be transferred into the register.

Abstract: A capacitance to digital conversion system wherein condition sensing capacitors and reference capacitors are arranged with circuitry including a virtual ground and means for providing an error signal related to the sensed condition. The capacitors, virtual ground and error signal means are disposed within a sealed housing so that the system is isolated from environmental influences and is hence more stable than like systems known in the art.

Abstract: This invention relates to electronic circuits that detect changes in digital data that occur on a parallel data bus. The data on the parallel input bus is fed to a memory register. In addition, each data bus is tied to a comparison circuit which compares the input data with the output data on the same bus. If the data is not identical, the comparison circuit changes state to provide a signal which may be used for updating the data.

Abstract: A navigational aid enables the effect of a course and/or speed alteration of one vessel on the nearest possible approach distance of another vessel to be calculated, using data readily obtainable from a simple relative radar display on said one vessel. The aid comprises a plurality of sealed manually-settable means for individually setting in data inputs respectively representative of the following:(1) the minimum nearest approach distance if no course or speed change is made;(2) the range of said other vessel;(3) the present speed of said one vessel;(4) the proposed course alteration;(5) the proposed speed alteration; and(6) the time for which the proposed course and speed will be held.The aid further comprises means to compute from the foregoing input data the resultant nearest possible approach with the proposed manoeuvre, and indicating means to provide an indication of said resultant nearest possible approach.

Abstract: A digital correlator compares two digital words a plurality of times. Each time the second digital word is shifted by one additional bit with respect to the first digital word. The results of the various comparisons are stored. The stored results are then searched to find the location of the results indicating the greatest similarity between the bits of the first and second digital words. This location is indicative of the number of bits by which the second digital word is displaced with respect to the first digital word when greatest similarity occurs.

Abstract: This disclosure deals with a system for indicating to the driver of a vehicle a figure which represents the operating efficiency of the vehicle and which is derived from the fuel consumed and the distance traveled by the vehicle. The system measures the speed of the vehicle and a characteristic of the fuel supply system of the engine which is indicative of the fuel consumption. These two factors are combined in a dividing circuit which produces a signal that is fed to an indicator for displaying the figure to the operator of the vehicle. The vehicle engine has a fuel supply system including injectors and a fuel pressure regulating apparatus. The total fuel flowing to the injectors is divided into a burned flow portion and a return flow portion, and the burned flow portion is a relatively fixed ratio of the total flow. The characteristic of the supply system which is sensed is the total flow, and because of the fixed ratio, it is indicative of the fuel consumption rate.

Abstract: A plurality of capacitive touch pad sensors are multiplexed to the input of a common charge transfer analog-to-digital converter (CTAD) under the control of a control logic circuit. The no-touch digital output of each touch pad is stored in a memory. The touch pads are then sequentially addressed and their output level is digitized in the CTAD and the digital output of each touch pad is compared to its no-touch value stored in the memory. If the digital value read is sufficiently different from the no-touch memorized value, a touch-detection signal is given. The no-touch digital reading in the memory is periodically updated, by a count of only one at most, if the updated no-touch value differs from the no-touch value in the memory.

Abstract: A thermal printer system for actuating a plurality of groups of thermal printing elements. The system includes a first circuit in which a plurality of data words are stored, the words representing the characters to be printed. A second circuit converts the data words into printing character codes. A selected bit from each code, which bit is sequentially altered, is supplied to a third circuit for actuating the printing elements.

Abstract: An apparatus for combining n independent, random binary streams into a single output stream in which the probability of occurrence of a binary "1" is of the form k/2.sup.n. The apparatus which may be easily implemented with a minimum of simple logic elements, includes a combiner for the random streams of the formf = x.sub.n ( . . . x.sub.3 (x.sub.2 x.sub.1 + a.sub.1) + a.sub.2 . . . ) + a.sub.n-1where x.sub.1, x.sub.2 . . . x.sub.n are independent variables representing flat random digital streams and a.sub.1, a.sub.2 . . . a.sub.n-1 are coefficients of the variables x.sub.1, x.sub.2 . . . x.sub.n having the value 0 or 1. Each value of k corresponds to a unique set of coefficients a.sub.1, a.sub.2 . . . a.sub.n-1 so that various probabilities of error may be easily obtained by a series of switches which select the appropriate values of the coefficients.

Abstract: A fan-shaped beam or a fan array of individual beamlets of penetrating radiation, such as X-ray or .gamma.-ray radiation, is directed through a planar slice of the body to be analyzed to a position sensitive detector. The fan beam and the detector are caused to move in a rectilinear or nearly rectilinear fashion so that the individual beamlets or rays of penetrating radiation scan across the body and each detector records a parallel ray shadowgraph at a different angle of rotation (scan angle) with respect to the body and covering a range of scan angles less than 180.degree. and typically approximately 90.degree.. The recorded shadowgraphic data is then reconstructed into a 3-D tomograph of the body using a method of successive approximations. The resultant scanner may be used to analyze planes of the body parallel to the major axis thereof such as saggital or coronal as well as transaxial planes.

Abstract: A system for analyzing a time-varying phenomenon in which the latter is repetitively initiated to provide a train of repetitive output signals. A fast Fourier transform interferometer is provied to scan the train. Data corresponding to a selected temporal resolution element having the same selected time position following initiation of each signal are sampled and the samples coded to improve signal-to-noise ratio. The time relation between a selected retardation point in the interferometer and the initiation of each signal in a given train is successively shifted so as to produce a series of coded data, each datum corresponding to a resolution element occurring at the selected time position but at a different interferometer retardation. The selected data are then assembled in their time sequence to generate a synthetic interferogram.

Abstract: A method and system for approximately indicating the temperature of molten steel is described. A temperature sensor is immersed in the molten steel and produces an output signal which indicates the temperature sensed by the sensor. The temperature output signal is sampled and a number of sample temperature values are produced. These values are stored by the system for evaluation. A plurality of stored sample values are intercompared, and if they fall within a given range, or band, of values, the existence of a temperature dwell is indicated. The system then calculates an approximate dwell temperature using the intercompared values.An alternative disclosed system additionally includes an oxygen sensor, related components and a switching network permitting the system to successively operate to approximate oxygen and temperature levels in molten steel.

Abstract: A micro-computer circuit including a read-only memory averages pulse information at a plurality of averaging levels with each averaging level corresponding to a progressively increasing maximum count level and generates a best estimate of the true mean rate of the pulse information wherein the best estimate corresponds to the average of the averaging level of the highest full count. If the pulse information remains stationary the averaging process continues to provide desired system resolution. If however the pulse information is determined to be non-stationary a new best estimate is developed to provide desired system accuracy. An optimum trade-off between system accuracy and resolution is thus achieved.