Nikola Tesla - Free-Energy Devices

90 INVENTIONS OF NIKOLA TESLA.but the continued weakening of a is attended by a subsequentweakening of b. Assuming the current to be an alternating one,a will now be reversed, while b still continues of the firstimpartedpolarity. This action continues the magnetic condition of &, followingthat of a in the manner above described. If an armaturefor instance, a simple disc F, mounted to rotate freely on anaxisbe brought into proximity to the core,a movement of rotationwill be imparted to the disc, the .direction depending uponits position relatively to the core, the tendency being to turn theportion of the disc nearest to the core from a to as indicated>,in Fig. 72.This action or principle of operation has been embodied in apracticable form of motor, which is illustrated in Fig. 73.Let AFIG. 74.in that figure represent a circular frame of iron, from diametricallyopposite points of the interior of which the cores project.Each core iscomposed of three main parts B, B and c, and theyare similarly formed with a straight portion or body