In order to broaden limited class of nonuniform transmission lines (NTL) for which known solutions are available, simple method of generalizing previously solved NTL problems is presented;it is shown that this method,...
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In order to broaden limited class of nonuniform transmission lines (NTL) for which known solutions are available, simple method of generalizing previously solved NTL problems is presented;it is shown that this method, which is applicable to all NTL, leads to classes of generalized NTL which include others in literature, such as proportional networks, generalized exponential lines, and generalized Bessel lines as special cases.
A method of applying impedance inversion to the grid-modulated amplifier is described. Two tubes are employed in the modulated stage with their plate circuits connected through the electrical equivalent of a quarter-w...
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A method of applying impedance inversion to the grid-modulated amplifier is described. Two tubes are employed in the modulated stage with their plate circuits connected through the electrical equivalent of a quarter-wave transmission line, and the modulating voltage is applied to the grids in series with the grid bias. By this means, high efficiency and large power output per tube are obtained. Efficiences of 65 to 80 per cent are readily secured during both modulated and unmodulated intervals as compared with 60 to 65 per cent for the high-efficiency linear amplifier. The output per tube is also greater than that of the high-efficiency linear amplifier. Only a small amount of modulating power is required, and this system is particularly adaptable to negative feedback. The effect of the impedance-inverting network on modulated waves is discussed. A simplified method of adjusting the tuned circuits of the impedance inverter is described. Formulas are derived for output and efficiency for both the high-efficiency grid modulator and the high-efficiency linear amplifier.
Given an n X n matrix, Z{s) composed of elements which are the ratio of polynomials in the complex quantity s, necessary and sufficient conditions of a general nature are found which are required for the existence of ...
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Because of its length, 270 miles, the 275 kv transmission line from Boulder Dam to Los Angeles, Calif., requires extremely high speed switching for stability. To meet the requirements, a high voltage impulse circuit b...
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Because of its length, 270 miles, the 275 kv transmission line from Boulder Dam to Los Angeles, Calif., requires extremely high speed switching for stability. To meet the requirements, a high voltage impulse circuit breaker, extending the oil blast theory to cover a multibreak construction with double cross-blast ports, has been built. It provides over-all switching times consistently less than 3 cycles (3/60 second). Approximately 10 per cent as much oil is used as in a comparable breaker of conventional design, and only 1/10 of this is exposed to arcing. Large factors of safety are provided over and above the interrupting rating of 5,000 amperes, 287 kv, or 2,500,000 kva. COPYRIGHT 1935 by the American Institute of Electrical Engineers.
This paper comprises an analytic study of dynamic voltages to be expected at the terminals of a tie-line circuit breaker during the separation of two parts of a system 180 degrees out of phase. Transient voltage crest...
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This paper comprises an analytic study of dynamic voltages to be expected at the terminals of a tie-line circuit breaker during the separation of two parts of a system 180 degrees out of phase. Transient voltage crests have been investigated on the analogue computer for a typical system under faulted and unfaulted conditions and the results are compared with oscillographic records obtained on an actual power system. Finally, high power laboratory data obtained on modern high-voltage circuit breakers opening fault currents at twice normal voltage and higher are evaluated in the light of the maximum possible duty indicated by the analytic study.
Equations are developed which accurately describe the characteristic impedance and signal propagation delay for narrow microstrip transmission lines. Differences in signal propagation delay for microstrip, strip line,...
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Equations are developed which accurately describe the characteristic impedance and signal propagation delay for narrow microstrip transmission lines. Differences in signal propagation delay for microstrip, strip line, and coaxial cables are compared as a function of dielectric constant. The characteristic impedance equation is verified through comparison with experimental results for impedance values from 40 to 150 ohms. The sensitivity of characteristic impedance to variations in physical parameters, such as dielectric constant, line width, and board thickness, is presented. Finally the equation is shown to yield exceptionally accurate results when the inherent inaccuracies of the physical measurements are considered.
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