Actual interruption of an a-c circuit depends upon the ability of the circuit breaker to prevent the re-establishment of the arc after the current goes through zero and the arc goes out. In some circuits full voltage ...
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Actual interruption of an a-c circuit depends upon the ability of the circuit breaker to prevent the re-establishment of the arc after the current goes through zero and the arc goes out. In some circuits full voltage appears across the contacts as quickly as 40 to 80 microseconds following the current zero. This recovery rate in volts per microsecond depends upon the triple product of: the current interrupted, the normal frequency of the system, and the recovery impedance in ohms of the external circuit. The calculation of circuit recovery rates is given in this paper by presenting in curve and table form the ohmic recovery impedance, and its components, for all the practical circuits found in the field. COPYRIGHT 1935 by the American Institute of Electrical Engineers.
To terminate pulse equipment supplying peak voltages up to a million volts for microsecond durations requires nonreactive loads to maintain the pulse characteristics. The resistive elements must not only dissipate the...
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To terminate pulse equipment supplying peak voltages up to a million volts for microsecond durations requires nonreactive loads to maintain the pulse characteristics. The resistive elements must not only dissipate the pulse energy but must also maintain a low reactance for the high frequencies in the pulse waveform. The return circuit, treated as a short-circuited transmission line, forms the basis for designing nonreactive resistors with both cylindrical and fiat conductors. The distribution of voltage, current, and power is shown for the ideal design. Formulas are derived for the Chaperon double winding, the "hairpin" or loop geometry, and the coaxial form. Resistance values range from less than an ohm to several hundred thousand ohms for pulse voltages up to 1.2 million volts. Time constants vary from 10 -6 to 10 -10 seconds. A frequency expression is derived to aid in predicting the resistor's frequency response. Construction and measuring techniques are included. Frequency effects are analyzed to compensate for the skin effect on the resistance and inductance, and to select low-loss dielectric materials.
This paper consists of two parts. In Part I, coupled-mode theory is employed to determine the effects of reflection at the various ports and unequal inductive and capacitive coupling coefficients on the coupling and d...
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This paper consists of two parts. In Part I, coupled-mode theory is employed to determine the effects of reflection at the various ports and unequal inductive and capacitive coupling coefficients on the coupling and directivity of two coupled lines. Since couplers utilizing microstrip lines generally have unequal inductive and capacitive coupling coefficients, the results presented here should be useful in explaining the behavior of microstrip coupled lines. It is shown how the difference in the coupling coefficients leads to finite directivity and, under certain conditions, to "codirectional" instead of "contradirectional coupling." In Part II, the coupling coefficients and other parameters of various microstrip-line geometries are presented. Using these parameters in the results obtained here leads to an improved understanding of and design criteria for coupled microstrip lines.
This paper describes some of the features of design and construction of the 110-kv. transmission lines of The Washington Water Power Compnay. A brief outline is given of the loads served and existing interconnections,...
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By interconnecting and coördinating its private communication facilities with the commercial telephone system, the Tennessee Electric Power Company is building up a comprehensive communication system for the use ...
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By interconnecting and coördinating its private communication facilities with the commercial telephone system, the Tennessee Electric Power Company is building up a comprehensive communication system for the use of all departments of the company. These improved communication facilities are described briefly in this paper. The principal features of the plan are: (1) adequate interconnecting facilities between telephone and power company systems are furnished by the telephone company;(2) telephone equipment retired by the power company is replaced by telephone company equipment;and (3) commercial leased service is considered whenever the power company requires additional facilities. COPYRIGHT 1935 by the American Institute of Electrical Engineers.
The purpose of this paper is to point out and explain some even harmonic phenomena which may attend the operation of star-star connected banks of transformers having grounded neutral on the line side only. Contrary to...
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In the type of circuits considered here, the input power is divided equally between two channels whose outputs are caused to have a very nearly 90° phase difierence over a broad frequency range. Networks suitable...
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The theory and performance of an electronically tunable transit-time oscillator are presented. The ferromagnetic resonance properties of a YIG toroid were used to magnetically tune the frequency of oscillation over a ...
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The theory and performance of an electronically tunable transit-time oscillator are presented. The ferromagnetic resonance properties of a YIG toroid were used to magnetically tune the frequency of oscillation over a 3000-MHz frequency range with a minimum output power of 1 mW at X-band.
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