Nikola Tesla Books
Books written by or about Nikola Tesla
Colorado Springs
July 21, 1899
Various arrangements with two sensitive devices for the purpose of increasing efficiency of receivers in telegraphy. Also for directing currents.
Two sensitive devices, disposed as indicated and so constituted that they break down or respond easier to impulses of one direction than to those of the other, allow the commutation of alternating currents. For this purpose a device may be employed, described before, consisting of a glass tube and two metallic plugs, the glass tube being about half filled with nickel chips or fillings of other metal. In Fig. 1. it is supposed that the devices a a1 have this quality which may be given, for instance, by a battery in each circuit as shown in Fig. 2. In both sketches 1) and 2) a relay R R is shown having one of its legs in one of the circuits and the other leg or coil in the second circuit. In this manner the impulses coming, for instance, from a distance as in telegraphy can be made to exercise an accumulative effect. The alternating impulses are led in through terminals t t.
Fig. 3. illustrates one of the connections of apparatus experimented with good success. The method of excitation and magnification by means of an oscillating transformer is used and the relay and secondary were connected either as shown in the plain lines or in the modification indicated by the Botted lines. The letters have the same meaning as in previous instances. In Diagram 4. similar connections are shown, merely the self-induction coil L has been done away with and secondary S adjusted accordingly.
94
July 21
In this setup a small excitation of one sensitive device is rapidly amplified by a feedback loop which acts via a transformer on the other sensitive device. Figure 10 shows how the receiver was excited by aerial (elevated metal ball C or C1) - earth system.
July 21
In continuation of work on receivers for continuous high frequency currents, he widens the researches on assemblies with two sensitive devices. He lays the sensitive devices out so that they are sensitive to impulses of one direction, which enables the alternating current commutation. On Fig. 1 and 2, relay coils are connected, so that the actions through both sensitive devices are added together. For other connections a small excitation of the sensitive device is quickly amplified, due to the action of the return link, which acts via the transformer. In Fig. 10, it can be seen how the receiver is excited by means of antenna systems (elevated metal sphere C or C1) - ground.
