GB107001A - - Google Patents

Abstract

107,001. Forest, L. de, and Logwood, C. V. May 23, 1916, [Convention date]. Electric oscillations, producing; thermonic deteclors and relays.-In wireless transmission systems of the kind in which oscillations are generated bv a vacuum-tube apparatus, the incandescent electrode is connected to one terminal of a condenser arranged in series with the inductance of the oscillating circuit, or to an intermediate point of that inductance. The invention is also applied to heterodyne receiving systems. As shown in Fig. 1, the vacuum tube 9 has its plate electrode 10 connected through a choking coil 15 and current source 14 to the filament 12. The aerial inductance 3 is connected through condensers 32, 6 to the plate 10 and grid 11 respectively. A series condenser 4 in the aerial has its lower plate connected through a condenser 7 to the filament 12, and the transmitting key 20 is placed in this connexion. For telephony, a microphone may be connected across the condenser 7. A high-resistance leak path 8 is provided between the grid 11 and the filament 12. In a modification, the aerial-earth capacity is replaced by a condenser in series with the inductance 3 and condenser 4 in the oscillating circuit. In another modification, the lead from the filainent is connected to an intermediate paint of the inductance 3, the condenser 4 being omitted. Fig. 4 shows the invention applied to heterodyne receiving-circuits, a battery 14, telephone 17, and flat spiral choking-coil 22 being connected in series across the plate 10 and filament 12. The other connexions are as described with reference to Fig. 1, except that the signalling-key 20 is omitted. A coil 23 of high impedance may be connected across the condenser 4, Figs. 1 and 4, to allow static charges on the aerial to pass to earth.