. An elementary manual of radiotelegraphy and radiotelephony for students and operators . tential of 20,000 or 30,000volts, or more, can be drawn. Transformers for radiotelegraphic purposes must be oil insu-lated. They consist of a primary circuit and secondary circuit ofinsulated copper wire wound over a laminated iron core, the wholebeing immersed in an iron vessel under highly insulating oil. Thecontaining vessel itself should be insulated, and the transformersgenerally have their primary or low tension circuits joined inparallel on the alternator, and their high tension or secondarycircuit
. An elementary manual of radiotelegraphy and radiotelephony for students and operators . tential of 20,000 or 30,000volts, or more, can be drawn. Transformers for radiotelegraphic purposes must be oil insu-lated. They consist of a primary circuit and secondary circuit ofinsulated copper wire wound over a laminated iron core, the wholebeing immersed in an iron vessel under highly insulating oil. Thecontaining vessel itself should be insulated, and the transformersgenerally have their primary or low tension circuits joined inparallel on the alternator, and their high tension or secondarycircuits may be joined in series. In working with extra high tension transformers used forcharging condensers, the utmost precautions must be taken to 56 DIG TELEGRA PN Y avoid touching any live wire, because such a mistake would inall probability be instantly fatal. Transformers have the power ofgiving a current far in excess of that which can be furnished by aninduction coil, hence the reason for extreme caution in handlingtiiem. If such a battery of high tension transformers has its. FiQ. 13. secondary terminals connected to a pair of spark balls, and if theseare also joined to the terminals of a battery of condensers C (seeFig. 14), we have an arrangement capable of producing electricoscillations of great power. Usually the alternator A produces an alternating currentat a voltage, say, of 2000 and frequency of 300 to 500. Thetransformers T transform up this voltage, say, to 20,000, corre-spondingly reducing the current. The condenser C is thuscharged to 20,000 or oO,000 volts or so, and the spark gap Smay be 5 to 10 millimetres in length. The condenser thendischarges across this spark gap at intervals, producing at eachdischarge a train of high frequency oscillations, the frequencybeing determined by the capacity of the condenser and the DAMPED ELECTRIC OSCILLATIONS 57 inductances, P, L, in series with it. It mi^ht be thought thatsince the charging voltage is alternating, or
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1916
