Nikola Tesla - Free-Energy Devices

HIGH FREQUENCY AND HIGH POTENTIAL CURRENTS. 315the maintenance of a vibration. But usually the E. M. r. on thecircuit or branch \a will be something like a 1 00 volts or so, andin this case it is not sufficient to break through the gap. Manydifferent means may be used to remedy this by raising the E. M. F.across the gap. The simplest is probably to insert a large selfinductioncoil in series with the circuit L. When the arc is166, the mag-established, as by the discharger illustrated in B'ig.net blows the arc out the instant it is formed. Now the extracurrent of the break, being of high E. M. F., breaks through thegap, and a path of low resistance for the dynamo current beingagain provided, there is a sudden rush of current from thedynamo upon the weakening or subsidence of the extra current.This process is repeated in rapid succession, and in this manner Ihave maintained oscillation with as low as 50 volts, or even less,across the gap. But conversion on this is plan not to be recommendedon account of the too heavy currents through the gapand consequent heating of the electrodes ; besides, the frequenciesobtained in thisway are low, owing to the high self-inductionnecessarily associated with the circuit. It isvery desirableto have the E. M. F. as high as possible, first, in order to increasethe economy of the conversion, and, secondly, to obtain highfrequencies. The difference of potential in this electric oscillationis,of course, the equivalent of the stretching force in themechanical vibration of the spring. To obtain very rapid vibrationin a circuit of some inertia, a great stretching force or differenceof potential is necessary. Incidentally, when the E. M. F. isvery great, the condenser which is usually employed in connectionwith the circuit need but have a small and capacity, manyother advantages are gained. With a view of raising the E. M. F.to a many times greater value than obtainable from ordinarydistribution circuits, a rotating transformer g is used, as indicatedat i la, Fig. 165, or else a separate high potential machineis driven by means of a motor operated from the generator G.The latter plan is in fact preferable, as changes are easier made.The connections from the high tension winding are quite similarto those in branch la with the exception that a condenser c,which should be adjustable,is connected to the high tensioncircuit. Usually, also, an adjustable self-induction coil in serieswith the circuit has been employed in these experiments. Whenthe tension of the currents isvery high, the magnet ordinarilyused in connection with the discharger is of comparatively small