Showing papers in "IEEE Transactions on Communication and Electronics in 1963"
TL;DR: A new data transmission technique has been evolved, which has the speed capability of the quaternary systems and, at the same time, promising performance.
Abstract: A new data transmission technique has been evolved, which has the speed capability of the quaternary systems and, at the same time, promising performance. An important advantage of this technique is that the amount of circuitry required and the degree of complexity are relatively low, being not much more than for a straight binary system and much less than for a typical quaternary system. The process is sufficiently general so that it is applicable to serial transmission over wire lines and parallel transmission over high-frequency radio circuits.
314 citations
TL;DR: In this paper, a high-voltage capacitance ratio bridge based on the current comparator principle is described and the inherent advantages of this bridge are high sensitivity and high accuracy without the necessity of a secondary balance.
Abstract: A high-voltage capacitance ratio bridge based on the current comparator principle is described. The inherent advantages of this bridge are high sensitivity and high accuracy without the necessity of a secondary balance. By suitable design the bridge is made direct reading in capacitance ratio and dissipation factor. It has a resolution of 1 ppm (part per million) and an accuracy of approximately 10 ppm. The highest capacitance ratio internally available with full resolution is 1,000/1. Design considerations and construction details are given. Possible applications are discussed.
41 citations
TL;DR: In this paper, the characteristics of the evolution of gas from metals in vacuum arcs are presented, and data are presented for electrode erosion for gas-free metals in the vacuum arc.
Abstract: The characteristics of the evolution of gas from metals in vacuum arcs are presented. New materials have been developed having ungettered gaseous impurity concentrations of the order of 1 part in 109. Loss of vacuum in a vacuum switch by desorption and by diffusion of helium and other gases is negligible when good techniques are employed. Data are presented for electrode erosion for gas-free metals in the vacuum arc.
28 citations
TL;DR: In this paper, a method for the measurement of the variation of capacitance with voltage in gas-dielectric capacitors is presented, which consists of applying to the capacitor a direct voltage and using a small alternating voltage to measure the capacitance variation.
Abstract: A method is presented for the measurement of the variation of capacitance with voltage in gas-dielectric capacitors. It consists of applying to the capacitor a direct voltage and using a small alternating voltage to measure the capacitance variation. The direct voltage coefficient obtained in this manner differs from that obtained with alternating voltage, and this relationship is studied theoretically and verified experimentally. High-voltage compressed gas capacitors can have appreciable voltage coefficients because of eccentricity in their electrode structure. A method is presented for detecting and correcting such eccentricity without opening the capacitor. The voltage coefficients of a few solid dielectric capacitors were measured by comparison with a known air-dielectric capacitor and the results reported.
27 citations
TL;DR: In this article, the authors used pushbuttons to activate voice-frequency tones for transmitting digital information from telephone stations to central offices to minimize the problem of digit simulation by speech, the signal frequencies were chosen to avoid harmonic relationships and the receiver employed several tools to reduce the problem further.
Abstract: Pairs of voice-frequency tones activated by pushbuttons are used for transmitting digital information from telephone stations to central offices. The signal receiver may be exposed to speech during interdigital periods. To minimize the problem of digit simulation by speech, the signal frequencies were chosen to avoid harmonic relationships, and the receiver employs several tools to reduce the problem further. Comprehensive field trial results indicate that this system will operate satisfactorily over all types of standard customer lines.
25 citations
TL;DR: In this paper, the breakdown and recovery strength characteristics of experimental vacuum interrupters incorporating a variety of contact materials were studied and it was shown that much of the breakdown strength for these devices is gained in less than a 1/8-inch gap length.
Abstract: A study has been made of the breakdown and recovery strength characteristics of experimental vacuum interrupters incorporating a variety of contact materials. Our data show that much of the breakdown strength for these devices is gained in less than a 1/8-inch gap length. Experiments using a synthetic test system indicate that these experimental switches recover nearly all of their breakdown strength in 1 to 15 ?sec (microseconds) after the cessation of peak arc current ranging from 400 to 3,200 amp (amperes).
24 citations
TL;DR: In this article, a very small-impulse voltage divider was designed for the measurement of steep-front impulse waves, and its errors were evaluated by the step-response method, using a pressurized sphere gap.
Abstract: A description is given of a very-small-impulse voltage divider which is insulated by compressed gas. The divider was designed for the measurement of steep-front impulse waves, and its errors have been evaluated by the step-response method, using a pressurized sphere gap. It was then used for measuring the volt-time curve of a sphere gap, and the results have been compared with those obtained by others.
20 citations
TL;DR: In this paper, the temperature distribution in a supercooled melt is qualitatively described and proper shaped heat shields are shown to overcome parasitic wall growth and thermal shock, besides being an additional means of controlling thermal conditions.
Abstract: The temperature distribution in a supercooled melt is qualitatively described. Properly shaped heat shields are shown to overcome parasitic wall growth and thermal shock, besides being an additional means of controlling thermal conditions. Using such a setup, it is possible to grow material in continuous sheets with a wide range of physical dimensions. The sheets are single crystals, dislocation-free, and have excellent surfaces.
19 citations
TL;DR: In this paper, the authors presented limited analyses of magnetic frequency-tripling devices and previously reported on an equivalent-circuit approach to the analysis and design of these devices, but this latter approach was still partly empirical in that the parameters from which the equivalent circuit was derived had to be determined experimentally.
Abstract: A magnetic frequency tripler is a nonlinear magnetic system which is used for the production of triple-frequency output from a 3-phase fundamental frequency source. Although triplers have been used extensively for certain applications, the design of these devices has until now been largely empirical. Earlier papers1,2 have presented limited analyses of magnetic frequency-tripling devices and the authors have previously reported on an equivalent-circuit approach to the analysis and design of these devices.3 This latter approach was still partly empirical in that the parameters from which the equivalent circuit was derived had to be determined experimentally.
19 citations
TL;DR: The problem of current chopping in the vacuum interrupter is considered and various reasons for the occurrence of this phenomenon are explored in this article, where it is shown that the presence of low work function materials also enhances arc stability.
Abstract: The problem of current chopping in the vacuum interrupter is considered and various reasons for the occurrence of this phenomenon are explored. Metals with high vapor pressure were found to be most suitable for the maintenance of an arc at low currents in vacuum, and have been utilized for the solution of the current chopping problem in vacuum interrupters. There is some evidence that the presence of low work function materials also enhances arc stability.
19 citations
TL;DR: The use of an addressable memory for an associative memory provides a flexibility which it is more difficult to achieve with a memory having associative features built into the hardware.
Abstract: The use of an addressable memory for an associative memory provides a flexibility which it is more difficult to achieve with a memory having associative features built into the hardware. One way to do this is to organize the information in the multilist structure which is the subject of this paper. This scheme has other advantages, such as very high efficiency of information retrieval in large and complex files, which can now be performed in real time.
TL;DR: Switched-mode transistor operation is known to provide greater efficiency than circuits using linear amplifiers as mentioned in this paper, and the improved circuit efficiency which results permits the carrier system to be considerably simplified and heat dissipation to be reduced.
Abstract: Switched-mode transistor operation is known to provide greater efficiency than circuits using linear amplifiers This paper describes some switched-mode circuits and shows how they are used in a high-density carrier system; the improved circuit efficiency which results permits the carrier system to be considerably simplified and heat dissipation to be reduced greatly
TL;DR: In this article, the principal results of a recent Bell System subscriber loop survey are discussed and statistically sound estimates of various physical and transmission characteristics of the loop plant are presented, useful in appraising the current transmission properties of the plant in the light of existing requirements.
Abstract: This paper discusses some principal results of a recent Bell System subscriber loop survey. Statistically sound estimates of various physical and transmission characteristics of the loop plant are presented. This information is useful in appraising the current transmission properties of the plant in the light of existing requirements. It provides a novel basis for evaluating new developments and services affecting present plant.
TL;DR: Analyses of two types of computational errors inherent in digital differential analyzer (DDA) operation are presented, with the emphasis on the statistical analysis of round-off error.
Abstract: Analyses of two types of computational errors inherent in digital differential analyzer (DDA) operation are presented. Even though the emphasis is on the statistical analysis of round-off error, truncation error is also discussed in detail. The basic functional block of the computer, the integrator, is represented by a transform. Transform representation leads to analytical simplification in that block-diagram algebra and other phases of transform theory can be applied. Analysis of a high-resolution type of DDA is introduced as an extension to the theory. Examples are illustrated in Appendixes I ? IV.
TL;DR: In this article, the synthesis of a class of a-c filters for use with high-power silicon-controlled rectifier (SCR) inverters is discussed and an example of one particular filter in this class is given and its characteristics are discussed in detail.
Abstract: This paper discusses the synthesis of a class of a-c filters for use with high-power silicon-controlled rectifier (SCR) inverters. Three features of the class of filters described include: (1) means to commutate or ?turn off? the SCR's in the inverter; (2) a voltage transfer function which is virtually independent of load impedance at the fundamental frequency; and (3) high harmonic attenuation for the purpose of producing a high-quality sine-wave voltage from a square-wave inverter. An example of the design of one particular filter in this class is given and its characteristics are discussed in detail.
TL;DR: Turn-off silicon-controlled rectifiers (SCRs) as discussed by the authors are a type of rectifier that can be turned on and off by gate current pulses of opposite polarities.
Abstract: The term ?turn-off silicon-controlled rectifier? relates to a 4-layer p-n-p-n switch, which can be turned on and off by gate current pulses of opposite polarities. Conditions for gate turn-off are analyzed by the carrier charge concept. Two methods for obtaining gate turn-off are developed and experimentally verified. Turn-off current gains of 1,000, and more, were measured. An estimate is made regarding larger turn-off SCRs (silicon-controlled rectifiers) of the future, and some applications are listed.
TL;DR: A theoretical analysis of variable-energy adaptive digital communication is given for a slowly-varying channel by providing the receiver with the capability of measuring signal-to-noise ratio, and controlling the transmitted signal energy by means of a feedback loop.
Abstract: A theoretical analysis of variable-energy adaptive digital communication is given for a slowly-varying channel. The adaptation is accomplished by providing the receiver with the capability of measuring signal-to-noise ratio, and controlling the transmitted signal energy by means of a feedback loop. Theoretical gains achievable with adaptation are calculated in terms of reductions in required mean transmitter energy as a function of a signal-fading parameter for different probabilities of unsatisfactory operation.
TL;DR: In this article, necessary and sufficient conditions are given for determining that a class of stationary random processes are ergodic in the quadratic mean, and the theorems given are wide sense theorem and refer to relations between temporal averages and probability averages for first-order statistics.
Abstract: Necessary and sufficient conditions are given for determining that a class of stationary random processes are ergodic in the quadratic mean. The theorems given are wide-sense theorems and refer to relations between temporal averages and probability averages for first-order statistics. This, however, is generally required in engineering applications.
TL;DR: Touch-Tone Calling as discussed by the authors is a telephone call initiation system that employs voice-frequency tones, controlled by actuating buttons, and is used on a trial basis to initiate telephone calls.
Abstract: A new system of initiating telephone calls employing voice-frequency tones, controlled by actuating buttons, and known as ?Touch-Tone Calling? is now in service on a trial basis. The resultant marked improvement in speed and ease of use appears to appeal strongly to telephone users. This system is described and the engineering and psycho-physical steps necessary to its development are outlined. Field tests of system feasibility and results obtained are discussed. Three companion papers present technical features of the system components.
TL;DR: The application of resonance techniques to the ratio transformer bridge is described in this paper, where the capacitance-to-inductance transfer makes it possible to refer all audio-frequency reactance standards to one group of standard capacitors.
Abstract: The application of resonance techniques to the ratio transformer bridge is described. The capacitance-to-inductance transfer thus achieved makes it possible to refer all audio-frequency reactance standards to one group of standard capacitors. Basic theory and alternate bridge balancing techniques are discussed. Significant sources of error are analyzed, and praceical numerical limits given. Experimental results are correlated with National Bureau of Standards (NBS) measurements. These results show a series resonance transfer accuracy better than 50 parts per million.
TL;DR: Artificially commutated converters are proposed in this article to eliminate the need for lagging a c supplies and lead a-c loads for conventional rectifying and inverting circuits.
Abstract: Artificially commutated converters are proposed in order to eliminate the need for lagging a-c supplies and lead a-c loads for conventional rectifying and inverting circuits. An artificial commutating circuit is present and analyzed. Expressions for the commutating time, overlap, and commutating energy requirements are derived. Test data show how an auxiliary voltage can satisfactorily cause commutation in those regions where reactive energy is returned to the a-c system of the static converter.
TL;DR: In this article, the reaction of the charged particles in an electric precipitator on the current was investigated and the major results were as follows: (1) duct precipitators are twice as sensitive to the presence of charged particles as pipe precipitors of the same interelectrode spacing; and (2) the intereceive spacing is the only geometric factor entering into the calculation.
Abstract: The problem under consideration is that of calculating the reaction of the charged particles in an electric precipitator on the current. The major results are as follows: (1) duct precipitators are twice as sensitive to the presence of charged particles as pipe precipitators of the same interelectrode spacing; and (2) the interelectrode spacing is the only geometric factor entering into the calculation. These results extend earlier work on pipe to duct precipitators.
TL;DR: In this article, two 2D signal representations based on angular prolate spheroidal functions are defined for use in signal analysis problems, and applications and numerical examples are provided.
Abstract: Two similar 2-dimensional signal representations are defined for use in signal analysis problems. The proposed procedure divides the time-frequency plane into rectangles of arbitrary length and width and assigns a certain portion of the represented signal to each such rectangle. Representations are based upon time-limited and band-limited forms of the angular prolate spheroidal functions for conceptual and mathematical reasons. Applications and numerical examples are provided.
TL;DR: The Touch-Tone caller as discussed by the authors is a dual-frequency oscillator capable of the generation of any one of 16 combinations of two frequencies under the control of a pushbutton actuated switching mechanism.
Abstract: The Touch-Tone caller is a dual-frequency oscillator capable of the generation of any one of 16 combinations of two frequencies under the control of a pushbutton actuated switching mechanism. Initial telephone sets for ordinary services will supply only ten signals. The oscillator design procedure is given and the mechanism is described. The characteristics of special components are discussed. Satisfactory performance of the new caller has been demonstrated in laboratory tests and field trials.
TL;DR: In this article, the characteristics of two capacitively coupled tuned anode oscillators and possible modes of oscillation are analyzed and possible use of the system as a frequency storage device is suggested.
Abstract: Characteristics of a system of two capacitively coupled tuned anode oscillators and possible modes of oscillation are analyzed. With certain adjustments of circuit parameters, asynchronous simultaneous oscillations are possible, while with other adjustments, single-frequency oscillations are obtained at one time. Possible use of the system as a frequency storage device is suggested.
TL;DR: In this paper, an active all-pass network with phase properties similar to that of the conventional L-C all pass lattice has been developed, which is unbalanced in form and requires one quarter as many phase-shift-determining reactive elements as the equivalent passive lattice.
Abstract: An active all-pass network having phase properties similar to that of the conventional L-C all-pass lattice has been developed. The network is unbalanced in form and requires one quarter as many phase-shift-determining reactive elements as the equivalent passive lattice. Limitations due to the active nature of the device can be overcome by proper choice of source and load impedances. The circuit has been experimentally verified.
TL;DR: In this article, glass ignitrons were studied carrying up to 21,000 amperes with rise times as short as 1.25?sec (microseconds). Kerr-cell photographs show discharge growth, constrictions, and an expanding circle of arc spots with speeds up to 2 × 106 cm/sec (centimeters per second).
Abstract: Glass ignitrons were studied carrying up to 21,000 amperes with rise times as short as 1.25 ?sec (microseconds). Kerr-Cell photographs show discharge growth, constrictions, and an expanding circle of arc spots with speeds up to 2 × 106 cm/sec (centimeters per second). The peak velocity varied with the 0.7 power of capacitor voltage and directly with the peak non-inductive component of anode voltage. Arc-front propagation, by ionic charging of a dielectric film, is discussed and is consistent with the measurements.
TL;DR: Methods for using error-detection and correction codes to check whether information from the proper address or from the Proper position in a time sequence has been received are described.
Abstract: Error-detection and correction codes are usually used to detect and/or correct errors in transmission or storage of information. This paper describes methods for using these codes to check whether information from the proper address or from the proper position in a time sequence has been received.
TL;DR: In this paper, a domain wall model consisting of semicylindrical domains at the surface of the material in the saturated state was used to describe irreversible flux changes in grain-oriented 50% nickel-iron (Ni-Fe) alloys, if these flux changes are produced by pulses of magnetomotive force (mmf).
Abstract: A domain wall model consisting of semicylindrical domains at the surface of the material in the saturated state can be used to describe irreversible flux changes in grain-oriented 50% nickel-iron (Ni-Fe) alloys, if these flux changes are produced by pulses of magnetomotive force (mmf). This model can also be used to describe certain small-signal reversible flux changes. The resulting analysis is applicable in the saturation region and in the case of small superimposed a-c signals during a large-scale flux reversal initiated by mmf drives.
TL;DR: In this paper, a method using steady-state transforms is described which indicates how the sum function of a Fourier series may be obtained, and several examples of the application of the method in circuit problems are given.
Abstract: A method using steady-state transforms is described which indicates how the sum function of a Fourier series may be obtained. The method can be applied to problems arising from circuits containing concentrated circuit parameters, but is not quite so useful for those having distributed parameters. Tables of Fourier series and their sum functions are presented, and several examples of the application of the method in circuit problems are given in this paper.