The Tesla High Frequency Coil: Its Construction and Uses

In presenting this book on the Tesla coil to the public, the authors hope that they have filled a long felt vacancy in the practical library of science. No attempt has been made to give a mathematical explanation of the oscillation transformer, and other parts of the high-frequency apparatus, for the simple reason that the theory is too complex, and when obtained, of no practical use. Neither have the authors tried to lead the amateur, who is just learning how to string bells and connect batteries, from the elements of the galvanic cell up to the working of a high-potential, alternating current, but have merely made an effort to place, in the hands of advanced amateurs in electrical science, a practical working manual on the construction of high-frequency coils, now so useful in scientific investigation.

The attention of the authors was first called to the Tesla coil when they were fortunate enough to be given the use of the 7" standard coil described in the last chapter of this book. A systematic line of experiments was carried on with it, in order to study the effects of a change in the constants of the various circuits. All the mechanical and electrical details of construction were carefully worked out, and the authors finally decided to design and construct a larger coil. The coil, as first constructed, was a decided failure, due to too small a condenser capacity. For about five months they further experimented on the details of construction and finally arrived at the 12" coil described in this book. This coil they feel assured is as efficient as can be made. It is especially designed to give a high-frequency discharge of great volume. This latter fact makes it useful for wireless telegraphy. In conclusion they have to thank Mr. G. O. Mitchell for many suggestions and for the kindly interest he has taken in this work. They feel that without his help the writing of this little book would have been impossible.