Nikola Tesla - Free-Energy Devices

316 INVENTIONS OF NIKOLA TKSLA.value, as it is quite easy to adjust the dimensions of the circuitso that oscillation is maintained. The employment of a steadyE. M. F. in the high frequency conversion affords some advantagesover the employment of alternating E. M. F., as the adjustmentsare much simpler and the action can be easier controlled.But unfortunately one is limited by the obtainable potential difference.The winding also breaks down easily in consequenceof the sparks which form between the sections of the armatureor commutator when a vigorous oscillation takes place. Besides,these transformers are expensive to build. It has been found byexperience that it is best to follow the plan illustrated at ma.In this arrangement a rotating transformer g, is employed toconvert the low tension direct currents into low frequency alternatingcurrents, preferably also of small tension. The tensionof the currents is then raised in a stationary transformer T. Thesecondary s of this transformer is connected to an adjustable condenserc which discharges through the gap or discharger dd, placedin either of the ways indicated, through the primary p of a disruptivedischarge coil, the high frequency current being obtainedfrom the secondary s of this coil, as described on previous occasions.This will undoubtedly be found the cheapest and most convenientway of converting direct currents.The three branches of the circuit A represent the usual casesmet in practice when alternating currents are converted. InFig. 15 a condenser c., generally of large capacity, is connected to thecircuit L containing the devices Z Z,m m. The devices mm are supposedto be of high self-induction so as to bring the frequency ofthe circuit more or less to that of the dynamo. In this instancethe discharger d d should best have a number of makes and breaksper second equal to twice the frequency of the dynamo. If notso, then it should have at least a number equal to a multiple oreven fraction of the dynamo frequency. It should be observed,referring to iJ, that the conversion to a high potential is alsoeffected when the discharger d d, which is shown in the sketch, isomitted. But the effects which are produced by currents whichrise instantly to high values, as in a disruptive discharge, areentirely different from those produced by dynamo currents whichrise and fall harmonically. So, for instance, there might be in agiven case a number of makes and breaks at d d equal to justtwice the frequency of the dynamo,"or in other words, there maybe the same number of fundamental oscillations as would be pro-