Nikola Tesla Books
CHAPTER VIII. KICKING COIL APPARATUS. The possibilities of the "kicking coil" type of high fre quency apparatus have long been recognized by manufacturers of electro-therapeutic outfits but, doubtless owing to the scarcity of published data on the subject, this simple and inexpensive generator of high frequency currents has not seemed to come in for its due share of popularity among amateur constructors. The kicking coil is an oddity to the uninitiated electrical worker; it is merely a winding of comparatively. coarse copper wire upon a core composed of a bundle of soft iron wires. In this simple coil, which is totally devoid of a secondary, is set up a current of sufficiently high potential to charge a condenser; this high potential is induced at every break of the circuit which permits current to flow through the coil. Fig. 1 represents a circuit of this nature. The kicking coil K is connected at one end of its winding with one side of the supply circuit. The other end of the winding goes to the vibrating armature of an interrupter. From the stationary contact of the interrupter we trace this circuit of the primary of a Tesla or Oudin coil and thence back to the source of supply. A condenser is connected across the break and the primary of the oscillation transformer. As the current flowing through the coil is interrupted, a high potential surge is set up. This current enters the 71
