US1152272A - Electric spark-gap. - Google Patents

Description

H. BOAS.

ELECTRIC SPARK GAP.

APPLICATION FILED OCT-22,1912.

Patented Aug. 31, 1915.

E/ecfmde lVa/dar 1 2 v mdes J d a m 0 HANS BOAS, 0F BERLIN, GERMANV.

ELECTRIC SPARK-GAP.

Specification of Letters Patent.

Patented Aug. 31, 1915.

Application filed October 22, 1912. Serial No. 727,247.

T 0 all whom it may concern Be it known that I, HANS Boris, of Berlin,

a subject of the King of Prussia, and residing at 52 Krautstrasse, Berlin, Kingdom of Prussia, German Empire, have lnvented a new and useful Electric Spark-Gap, of which the following is a specification.

It is known by the experimental work of Tesla that a spark gap consisting of a large number of single spark gaps with very small distance between the electrodes is very useful in producing electric oscillations. Wlen has found that the reason for this fact is the large damping action on the electric v1brations, and that by coupling in a certain man nor the circuit containing the spark gaps with a secondary circuit having capacity and self-induction, a transfer of electrlcal energy can be effected in the same manner as it is effected by exciting the secondary circuit by the primary by one impact only. On this principle is also based the spark gap of Lepel who uses flat plates of metal arranged a small distance from each other.

The large plate was intended to exert a cooling eifect on the spark, and for this reason he and others have used plates of silver or copper. With these spark gaps a coupling up to 19.5% could be obtained as degreeof' much upon the kind of the material used for the electrode. For instance using silver or copper-electrodes a distance smaller than 0.01 mm. is impracticable because these electrodes melt together by the heat of the sparks. With electrodes of platina-iridium a much smaller distance can be used, less than the half,'because the pIatina i-ridium by reason of its hi h melting point and its me chanical strengt opposes a much larer resistance to the melting by the heat of the spark. The platina-iridium, however, has certain disadvantages. It is relatively easily evaporated, and this evaporation alters the distanceof the electrodes. In the spark gap itself there is much metal vapor exerting a disturbing effect on the action of the spark gap. Y M

I have now found that tungsten is a ma' terial which is better suited for the con;

struction of spark gaps than any other material. The tungsten is unmeltable at the temperatures which can arise and is not liable to be destroyed by being atomized into minute articles, which form a kind of a dust,

and dissolve into spray. The consequence is that two electrodes of. tungsten can be adjusted at very much smaller distances without danger of a short-circuit by the melting of the electrodes. With the tungsten there is practically no spraying action and there:

fore no vapor in the spark gap. The elec-- trodes are practically indestructible so that' the distances of the electrodes once determined are nearly continually maintained. The use of tungsten permits of a further reduction of the diameter of the electrodes. The spark between the tungsten electrodes is nearly noiseless and-has no tendency to surpass the edges of the electrode, the consequence being that with aspark gap having tungsten electrodes practically pure sounds are produced. Even ,if there is a wrong coupling between the primary and secondary circuit there is no essentia/l alteration-of the sparks between the electrodes so that the wrong coupling has no disadvantageous in: fluence on the spark gaps of tungsten. These excellent qualities which are peculiar to spark gaps having electrodes of tungsten.

allow, without p'rejudicing the operation, the

obtaining of critical coupling degrees of more than 45% between the primary and secondary circuit. It may be. said that the tungsten air gap is a-source of energy for producing the vibrations of high frequency that are substantially perfect, and which were not known heretofore.

I have. illustrated in the accompanying drawings a quen chedspark gap with tungsten electrodes embodying mydnvention.

In a sim' ar way as tungsten tantalum .and molybdenum may be used for the shine purpose;

What I do -eleim as my invention,- and desire to secure'by Letters Patent of the United 5 States, is

1. In quenched sparkgaps for producing I quickly'quenched vibrations, an electrode consisting of tungsten. 2. In quenched spark gaps for producing .IIGSSGS.

uenched vibrations, electrodes con- 0 1 l HANS BOAS. Witnesses HENRY HASPEB, Y WOLDEMAR

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