The Journal of the Institute of Electrical Engineers of Japan

Lightning Arrester from a Certain Point of View

HIDETSUGU YAGI

1923 Volume 43 Issue 417 Pages 279-299
Published: 1923
Released on J-STAGE: November 20, 2008

DOIhttps://doi.org/10.11526/ieejjournal1888.43.279

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1. Introduction.
It is often stated that an ideal lightning arrester should quickly relieve the system of excess voltages, but should not allow any flow of the dynamic current of the system.
It is shown in this paper that the statement is vague and unscientific and that it is almost impossible to design a truly ideal arrester by the principle of a discharger.
2. Solution using the effective values of alternating electrical quantities.
After discussing the series resistance of a horn arrester, the superiority of a multigap type is demonstrated. A formula is derived which gives the magnitude of the series resistance required for a give numeber of air gaps.
The shunt resistance is then determined that would make the arc unstable. The discharge characteristic of an aluminum cell arrester is also considered. It is shown that the volt-ampere characteristic, which simply gives the relation between effective values, is entirely inadequate to cope with the discharge phenomena, which generally contain complicated and abrupt changes of instantaneous values.
3. Solution considering the instantaneous phenomena.
In order to understand the instantaneous phenomena, the dynamic characteristics muts be considered. But the dynamic characteristic is indeterminate unless the form and the magnitude of the lightning disturbance are given.
It is especially difficult to discuss the discharge of an aluminum cell lightning arrester since its dynamic characteristic has yet been very little studied.
4. Behaviour under abnormal voltages.
Refering to the following three cases, it is shown that, even if the arrest- er behaves so well as to perfectly satisfy the generally accepted conditions, the useful A.C. is apt to be discharged while the disturbing forms of potential are retained in the line, so that the step out of synchronous machines becomes inevitable.
i When the lightning is a high frequency oscillation of short duration.
ii When the lightning is a high frequency sustained oscillation.
iii When the lightning is a low frequency or a static potential.
5. A device on the alum num cell arrestor.
The possibility of utilizing the static capacity of the cell arrester as a high frequency absorber is pointed out. The author-proposes for this purpose the use of a shorter air gap with series resistance and also a static condenser in parallel with the simple air gap hitherto employed.

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Commutation in D. C. Machines

M. TERADA

1923 Volume 43 Issue 417 Pages 300-323
Published: 1923
Released on J-STAGE: November 20, 2008

DOIhttps://doi.org/10.11526/ieejjournal1888.43.300

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In modern practice the majority of d c. machines have commutating pules by which t'e indnced e.m.f s. in armature coils undergoing commutation are compensated. Since, however, the compensating action in only done in the mean value some e m.f.s. may still remain uneompensated, the values of which being sometimes as high as nearly equal to the mean inducel e.m.f s. compensated and unsatisfaetery commutation will result.
Thus the uncompensated e.m.f.s must be paid carefull attension for rather than the mean value of the induced e.m.f. or the so-called. "reactance voltage." Since this uncompensated e.m.f. is due to the pulsation of the induced e.m.f. and the compensating e.m.f. it is an alternating e.m f. consisting of e.m.f. of tooth frequency and that corresponding nearly with period of commutation. Study of this problem needs carefull analyzation of phenomena. This has been done in this paper to a certain extent though much would yet be remaind for prae tical application.

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Present Condition of Radio Telegraphy and Telephony in Europe and America

ISAMU YAMAMOTO

1923 Volume 43 Issue 417 Pages 324-352
Published: 1923
Released on J-STAGE: November 20, 2008

DOIhttps://doi.org/10.11526/ieejjournal1888.43.324

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On Printing Telegraph

S. SUZUKI

1923 Volume 43 Issue 417 Pages 353-363
Published: 1923
Released on J-STAGE: November 20, 2008

DOIhttps://doi.org/10.11526/ieejjournal1888.43.353

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On the Oscillations prcduced by means of a Tungar Rectifier

YASUSI WATANABE

1923 Volume 43 Issue 417 Pages 364-372
Published: 1923
Released on J-STAGE: November 20, 2008

DOIhttps://doi.org/10.11526/ieejjournal1888.43.364

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This is the supplementary note for the paper "On the characteristics of the arc of Tungar Rectifier" published before by the same author.
Oscillographic studies of the oscillating currents produced by means of a tungar rectifier are performed, namely on a direct current arc and a rectifying arc.
This report treats of the relation between the oscillation and the heating condition of the filament, which forms the cathode of the arc.
When the filament current is of comparatively small value, being less than several amperes, oscillating currents of relatively high audio-frequency are produced traversing the condenser connected across the terminals of the tungar bulb. This oscillation may be considered to be due to an ionic oscillation of negative ions in the arc, as was stated in the previous paper.
When, however, the filament current is increased up to more than fourteen amperes, an intermittent current is suddenly produced in the condenser circuit, which is of low frequency at several hundred cycles per second and is of effective value as high as one ampere.
The reason that such an intermittent current is produced may be explained from the dynamic characteristic curve of the oscillating arc, which can be constructed from the wave form of the intermittent current in, the condenser circuit.
In order to oscillographically observe the oscillations produced by the rectifying arc, the well-known Hull's circuital arrangement for the rectification with kenotron is used.
Considering the relation between the currents flowing in differents parts of the circuits, we can distinctly observe that an oscillating current of audio-frequency is superposed on the current flowing through the rectifier, and that the more the filament current is increased, the less is the frequency of the oscillation reduced, exactly as was the case for a direct current arc.

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[title in Japanese]

[in Japanese]

1923 Volume 43 Issue 417 Pages 377-383
Published: 1923
Released on J-STAGE: November 20, 2008

DOIhttps://doi.org/10.11526/ieejjournal1888.43.377

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