Nikola Tesla Books
THE HIGH POTENTIAL TRANSFORMER mm 19 Fig. 3.-Typical oscillatory circuit showing how high frequency current is generated by means of the condenser discharge method for the charging of condensers, the experimenter knew but little of the requirements of the process. The only high tension transformers available were of the power variety with closely coupled primary and secondary, and the first trials of these gave such promising results that the workers were induced to carry on an extensive line of research with a view to improving the apparatus. One great difficulty was experienced from the start. A glance at Fig. 3 shows that the secondary terminals of the transformer are shunted by the spark gap, which in turn is shunted by the condenser and primary of the oscillation transformer in series. When the condenser discharges across the spark gap, the discharge produces a short circuit for the secondary current in the transformer after the spark has died away. This causes an arc to form with the result that the condenser cannot charge again as it should. The close coupling of the windings tends to hold the secondary voltage at its maximum when the short circuit occurs. Various experiments were tried to prevent the formation of the arc, and among these may be mentioned a magnetic blow out, which aided in quenching the arc; a blast of compressed air between the spark gap electrodes, which
