Abstract: An arrangement is shown for combining multisource randomly occurring data, such as seismic or sonar data, into a single output signal. Histories of simultaneously occurring data from each source are accumulated, and their power levels compared to determine which is likely to have significant data, as distinguished from noise. The largest of the data so compared in a given time epoch determines the source to be used in a succeeding epoch to provide the output contribution for that succeeding epoch.

Abstract: A binary full adder, including provision for carry digits, is implemented using metal-oxide semiconductor field-effect transistors (MOSFET) in the exclusive-OR configuration. The improved structure realizes economies in space occupancy, and device topology, reduction in power requirement and no loss in propagation time over prior full adders employing conventional logic structures.

Abstract: In a stored program controlled electronic telephone switching system transmission links are provided from a host office, provided with a central processor, to one or more remote offices, each provided with a remote processor. Data and control information are continually passed between the host office and each remote office in a digital time-division format. Data integrity is monitored through a cyclic odd and even patterned parity scheme which predetermines the parity of sequential time slots in one direction of transmission and reflects that parity pattern in the return direction of transmission between host office and remote offices. The patterned parity scheme detects hardware faults in the interface for the transmission links between host and remote offices on a continuous basis.

Abstract: A differential pulse code modulation system is made adaptive to quantization noise in a way which permits variable-rate operation as either a conventional R-bit embedded code or as a combination of a conventional R-bit code and a further explicit noise code with instantaneous quantization. Additional improvement in signal-to-noise ratio is attainable by using a noninstantaneous variable-bit allocation procedure for equal-length sampling blocks with an averaged fixed bit code.

Abstract: A microprocessor controlled condition sensor comprising a parallel multiport microprocessor, precision resistor, capacitor, and one or more transducers (e.g., thermistor) determines the value of the condition being sensed (e.g. temperature) by calculating the resistance of the transducer through the ratio of interval 0/1 threshold timings determined by the RC time constants of precision resistor-capacitor and transducer-capacitor connections. The value of the condition (e.g., temperature) is subsequently obtained via a lookup table within the microprocessor which contains the relationship between transducer resistance and condition magnitude.

Abstract: Method and apparatus for the rapid generation of discrete random variates, of a general probability distribution, from random variates of a uniform distribution uses simple logic and moderate storage requirements. Access to a first table at an address which is a function of a uniform variate gives the desired variate value directly for a large percentage of cases and in the remaining cases the desired variate value is obtained by an indexed search of a second table of cumulative distribution function values. Results of greater precision are realized in faster execution times with less logic complexity and reduced storage bulk as compared with prior methods and apparatus.

Abstract: A balanced modulator, producing a double sideband suppressed carrier (DSBSC) output achieves carrier suppression and linear performance suitable to modulate frequency division multiplexed signals with stringent interchannel interference requirements. It is simply and inexpensively realized through the use of two logic gates which are arranged in a dual complementary fashion, so that their output terminals go high and low alternately, and which drive a center-tapped transformer through coupling capacitors to provide the required switching function necessary to produce the DSBSC output. The modulator circuit has the added feature that the square wave carrier source that is applied to the logic gates can be the means of activating the circuit, thereby eliminating the need for a separate power supply.

Abstract: A majority vote circuit determines when the majority of a group of signaling channels is properly conveying a common message in conjunction with a status signal individual to each channel. Respective status and message signals from each channel are scanned in pairs and in sequence. The number of valid message and status signals are accumulated in separate counters. A comparison circuit triggered by the completion of a scanning sequence matches counter outputs stage by stage to determine whether or not the count level in the message signal counter exceeds by one-half the count level in the status signal counter as an indication that a majority of a variable majority of the working channels conveys the same message signal.

Abstract: Apparatus and method (FIG. 1) for testing inductively loaded telephone transmission lines for immittance irregularities approximate a ladder network of series inductors and shunt capacitors equivalent to the input impedance of the transmission line from the pole and zero frequencies of the differential phase versus frequency characteristic thereof. The differential phase function is obtained (FIGS. 5 and 6 combined or FIGS. 5 and 7 combined) as the Hilbert transform of the logarithmic difference between a direct and delayed impedance measurement extending over a swept-frequency range in the voice-frequency band. Inductance values of the ladder network are proportional to the inductances of the line loads and the capacitor values are proportional to the distances between load inductors spaced along a transmission line.

Abstract: Computer graphics material after raster scanning and digitizing is examined for linear narrow width areas of like light value, typically black or white. Runs of like value on successive scan lines are compared for contiguity and, when found, are compactly coded by coordinates of first and last scan lines defining each area and thickness. Data compaction ratios up to 36 to 1, as compared to the amount of data required to store data for every picture element, can be achieved in real time.

Abstract: Binary digital data signal patterns containing either no transitions, periodically recurring transitions or both are randomized by constructing a key signal from a summation of selected stored digits of the data pattern and combining such key signal with the data signal to form a scrambled line signal for transmission. The line signal so constructed is free of signal energy concentrated at particular frequencies and provides signal transitions adequate in number to assure reliable recovery of synchronization information. Descrambling of the received line signal is accomplished by precisely the inverse of the scrambling operation. The system is self-synchronizing because the key signals constructed by each of the scrambler and descrambler are derived from the same line signal.

Abstract: Disclosed is a feedback regulated oscillator which comprises a reference signal source, a variable local oscillator, a converter responsive to the variable local oscillator for developing a signal, compatible with the signal of the reference source, having a magnitude which is responsive to the frequency of the local oscillator, and a comparator, responsive to the reference signal source and to the converter, for controlling the frequency of the variable local oscillator.

Abstract: A connector (10) comprising an index strip (100) with wire-retaining slots (112) for receiving individual conductors (20), a connector module (200) with wire-engaging contact elements (40) and an index-strip portion (203), and a module cap (300). The wire-retaining slots (112, 212) in the index strip and index-strip portion of the connector module have flexible inwardly curved flanges (130, 230) adjacent to one end of the slot. Each corresponding pair of flanges, which depend from adjacent slot-defining upright members (110, 210), deflect inwardly into the wire-retaining slot during wire indexing to securely grip an inserted conductor (20, 30), the deflected flanges being capable of biasing toward each other to create an even tighter grip on a conductor when conductor pull out from that end is attempted.

Abstract: An image composed of binary black and white picture elements (pixels) is progressively transmitted over a narrow-band channel after binary values of all pixels have been formatted into a hierarchical structure of subdivisions of successive halvings from the entire image down to cells of pixels of uniform size and shape. Each formatted value is encoded in accordance with whether the pairs of values from which it is derived are both black, both white or mixed. Transmission of the hierarchical values involves sending the primary value representing an overall midgray mixed value, and following with successively split image values so that the entire image is reconstructed at a remote receiver in progressively finer detail down to cell size. Final resolution, when needed, results from decoding a variable length code for the permutational patterns of pixels within cells in accordance with their probabilities of occurrence.

Abstract: An arrangement for aligning single-track magnetic record/reproduce heads in magnetic tape transports in both azimuth (skew alignment) and track position (vertical alignment) employs a single test tape. Dual test tracks within the width of a single head contain prerecorded blocks of pulses of alternating polarity, respectively uniformly and nonuniformly spaced. The nonuniformly spaced pulses are increasingly separated from each other in each block from a value below to a value above, and passing through, the uniform spacing of the other track. Reading the two tracks simultaneously from the head being aligned mixes the separate pulse trains to form a wave pattern with a symmetrically centered null in each block when the head is properly aligned and a nonsymmetrically located null of varying depth when the head is improperly aligned. It is unnecessary to move the head while the type and degree of misalignment is being determined. Alignment adjustment can be performed while the test tape is being read.

Abstract: A fault on a nonloaded telephone subscriber loop is sectionalized by a frequency domain distance detection system. The derivative with respect to frequency of the phase angle of the complex input impedance of a cable pair is continuously monitored over a swept-frequency range beyond the voice-frequency band. The phase itself is obtained indirectly as the Hilbert transform of the logarithmic differences between the instantaneous impedance and a delayed version thereof. Thus, circuitry which is less sensitive to noise, parameter variation, and measurement error than prior techniques becomes practical for generating waves having energy peaks corresponding to the distance from the measurement end of a loop under test to impedance irregularities therealong.

Abstract: In the prior art key control signals are produced at a scrambling location, used at that location for scrambling and then transmitted along with the scrambled message to the unscrambling location. In accordance with the present disclosure, improved privacy is achieved by producing key control signals at the unscrambling location, using them at that location for unscrambling and also transmitting them to the scrambling location for use in scrambling.

Abstract: A digital counter driven by a stable high frequency source generates a periodic signal synchronized to an external signal source. Gating circuitry responsive to particular digital counts, accumulated by the counter, defines precise quantized time intervals. The external signal is examined during these quantized time intervals for the occurrence of significant cyclic events such as zero crossing. A single occurrence of cyclic event is determined during a first time interval while successive multiple occurrences of the cyclic event are searched for during a second but smaller time interval. In each instance failure of the event searched for activates corrective circuitry to inhibit synchronous oscillation with the external signal source.

Abstract: A mobile microphone-transmitter assembly is disclosed which comprises a microphone, a plurality of infrared light emitting devices, electrical apparatus connected between the microphone and the devices to energize the devices in response to inputs to the microphone and a mechanical structure for supporting the devices to produce a substantially omnidirectional, horizontal radiation pattern when the structure is worn by a user and the devices are energized.