GB398546A - Improvements in circuits for modifying the wave-form of electric signals such as telegraph signals - Google Patents

Abstract

398,546. Code telegraphy. STANDARD TELEPHONES & CABLES, Ltd., Connaught House, Aldwych, London.- (Assignees of Materiel Telephonique Soc. Anon. ; 46, Quai de Boulogne, Boulogne-sur- Seine, France. March 18, 1932, No. 8075. Convention date, March 21, 1931. [Classes 40 (iii) and 40 (v).] A wave-shaping device comprises a thermionic valve back-coupled through a gaseous discharge tube. Fig. 1 shows a known shaping device in which the plate circuit of valve T includes a neon or other discharge tube N together with a resistance R, resistance or choke R<1>, and batteries E, E<1>. For a given range of signal - strengths a continuously varying input at terminals 1, 2 yields a discontinuous output at terminals 3, 4. Another rectifying system is obtained, Fig. 8 (not shown), by rearranging the parts shown in Fig. 8. In a modification, Fig. 11, the input transformer Tr is in series with a resistance-capacity combination R<1>, C, the output relay L is shunted by a wave-shaping condenser C<1>, and a choke Z is provided ; the grid is coupled through resistance R to the plate circuit which includes the discharge tube N. The circuit may include further amplifiers, Fig. 12 (not shown), or mutual inductance, Fig. 13 (not shown), and the branch containing the tube N may be electromagnetically coupled to the choke Z and to the grid circuit, Fig. 14 (not shown). The valve T may be replaced by a push-pull pair, Fig. 15 (not shown). The resistance R in any of the above arrangements may be replaced by the plate-filament path of a thermionic valve. According to the Specification as open to inspection under Sect. 91, two systems of the kind shown in Fig. 1 may be used in cascade, Fig. 7, cancelled, (not shown) for squaring wave-forms, one tube N being active when the other is extinguished. The input connection 2 may be tapped off the resistance R, R<1>, as shown in Fig. 8. 7, so that the grid bias is affected by the current through the tube N. Fig. 9 (cancelled) shows a rectifying system. Alternating-current impulses applied to terminals 1, 2, cause the tube N to strike but are prevented by the filter F from reaching, the valve T. Signals determined by the striking and extinction of the tube N are passed on to the valve. Two three-electrode discharge tubes N, N<1> may be coupled, as shown in Fig. 19 (cancelled) so that when alternating voltage of any wave-form is applied to the input terminals 1, 2, the tubes N, N<1>, are alternately opened and closed. This subject-matter does not appear in the Specification as accepted.