Patent GB-190308509-A (GB)
Title: Improvements in Wireless Telegraphy
Inventor: THOMPSON WILLIAM PHILLIPS
Filed: 1903-04-14
Granted: 1903-12-17
Abstract: 8509. Thompson, W. P., [Stone, J. S.]. April 14. Telegraphs; telephones.-Extensions and improvements are described in the apparatus and systems of Specifications Nos. 27,272 and 27,253, A.D. 1902, for the purpose of transmitting and receiving wireless telegraphic signals consisting of combinations of Hertzian waves of different frequencies lasting for different periods. Definite sequences and combinations of these waves only are recorded, the signals thus received being distinct from any obtained by single resonators tuned to one of the frequencies. Fig. 9 shows a cylinder E, and three others similar to it, having contact plates x, y in different positions thereon and connected to the axles. When a cylinder is rotated by means described in Specification No. 8508, A.D. 19U3, contact brushes e, f, b cause the battery B<9> to energize relays R<9>, R<10> and complete circuits M', M', containing the alternators A and the primaries of transformers, the secondaries of which are combined with condensers, spark-gaps, and impedance coils as shown, so as to cause radiations from conductors V, of waves of frequency X, Y, respectively. Transmitters for sending waves of three frequencies are described, and also perforated strip contact-makers, which may replace the cylinders. Fig. 1 shows by dotted lines the relative duration of the X, Y waves for different positions of the contact-pieces. The lines S represent the durations of signals recorded by apparatus actuated by the Y waves only after the cessation of the X waves, the upper figures corresponding to the dots and the lower to the dashes of the Morse code. Fig. 7 shows arrangements for recording signals from waves Y after other waves X, Z have been received and the waves Z have ceased, as indicated in Fig. 8. Waves X energize the relay in a coherercircuit controlling the contact k<31>, thereby causing the relay R<31> to close the switch S<31>. When waves Y similarly effect closure of the contact k<32>, the circuit 33 is completed, and consequent completion of the circuit 34 by the relay R<33> ensures that the circuit 33 shall not be broken when the waves X cease. Contact s<53> has thus been closed. Upon the waves Z closing the contact k<51>, the circuit 514 is completed, and when the waves cease the battery B<514> or the relay R<51> effect completion of the circuit 55, and the consequent closure of the contact s<51> is recorded by the translator T. Circuits 56, 57 and contact s<57> provide for breaking the circuit 514, when waves Y cease. Telephone receivers v, Fig. 12, may obviate the use of relays as described. Circuits 12, 13 contain batteries and coherers D, D, consisting of a steel or other metal point in contact with an aluminium or carbon plate. The windings n<13> of the telephone receiver are in the circuit 13, and other windings n<12> form a shunt across the battery B<12>. When waves Y reach the conductor, the coil n<13> is energized and the telephone sounds unless waves X are also reaching the conductor and reducing the currents in the coil n<12>. Blind or non-signal-transmitting waves may also be sent further to guard against detection.