. An elementary manual of radiotelegraphy and radiotelephony for students and operators . 76 RADIOTELEGRA PH Y is the spark potential corresponding to the length of spark gap Iemployed. Hence the attempt to increase V involves an increasein /, and this involves an increase in the resistance of the spark,and therefore a larger damping in the circuit, and therefore feweroscillations per train. Hence the integral effect of the oscillationsas estimated by the heating effect of the whole of the train whenpassed through a line wire is not necessarily increased, but maybe decreased by increasing the
. An elementary manual of radiotelegraphy and radiotelephony for students and operators . 76 RADIOTELEGRA PH Y is the spark potential corresponding to the length of spark gap Iemployed. Hence the attempt to increase V involves an increasein /, and this involves an increase in the resistance of the spark,and therefore a larger damping in the circuit, and therefore feweroscillations per train. Hence the integral effect of the oscillationsas estimated by the heating effect of the whole of the train whenpassed through a line wire is not necessarily increased, but maybe decreased by increasing the spark length. We diminish thenumber of oscillations in a train if we try to increase the ampli-tude of the initial oscillation. It appears therefore that there isa certain length of spark gap which gives the least damping andtherefore greatest integral effect, and this appears to correspondto a very short spark length in air of about 1 mm. or less. Ordinary Spark. Primary Secondary Prunary Secondary Fig. 24.—Diagram denoting the nature of the oscilla-tions in the primary and secondary circuits for anordinary and for a quenched spark. 9. ftuenched Spark Methods for the production of DampedOscillations.—Kecent methods for the production of dampedoscillations generally employ some form of quenched spark inwhich the spark resulting from the discharge of a condenser israpidly extinguished. This method is based upon a discoverymade by M. AVien in 1906 on the damping of short sparks. If acondenser is discharged across a spark gap which is more thana millimetre or so in length, then provided there is sufficient DAMPED ELECTRIC OSCILLATIOyS 77 inductance and capacity in the circuit and also not nuioh resist-ance, the discliari;e is prolou^ed ami a series of oscilhitions takesplace before the condenser is iiually discharged. If tlien thiaprimary circuit is coupled iiuluctively to a secondary circuit thetwo act and react on each other as already descr
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttelegra, bookyear1916
