Nikola Tesla U.S. Patent 725,605 - System of Signaling Patent Wrapper Page 27

inductance of one of the primaries. It should be stated, furthermore, in regard to the apparatus illustrated in Fig. 2, that special and useful results are obtainable by connecting contacts and in multiple arc instead of in series, as shown, in which case the relay R³ will be necessarily so constructed or adjusted that it will not be operated unless both of the contacts are closed. Obviously there is no necessity for using transmitters. with two or more distinct elements or circuits at the same station, since a succession of waves or impulses of different characteristics may be produced by an instrument ravirg but a single circuit. circuit. A few of the many ways which will readily suggest themselves to the expert who applies my invention, are illustrated in Figs. 3, 4 and 5. In Fig. 3 a transmitting system e s3 d³ ishartly shunted by a rotating wheel or disk D3, which may be similar to that illustrated 3 4 in Fig. 1, and which cuts out periodically a portion of the coil or conductors, or, if desired, bridges it by an adjustable condenser c3, thus altering the wibration of the system e s³ d³ at suitable intervals and causing two distinct vibrations to be emitted in rapid succession by the sender. In Fig. 4 a similar result is produced in the system es by periodically short circuiting the primary p by a rotating disk with insulating, and conducting segments, or otherwise. Again, in Fig. 5 trèe distinct vibrations are caused to be emitted by a system e s5 d, the result being produced by inserting periodically a suitable number of turns of an induction coil L in series with the oscillating system by means of a rotating disk D5 with two projecticns 25 25, and three rcds or brushes n, placed at an -9641