| 摘要 |
454,541. Converting. SIEMENSSCHUCKERTWERKE AKT.-GES., Siemensstadt, Berlin. March 10, 1936, No. 7259. Convention date, April 3, 1935. [Class 38 (ii)] In a polyphase converter comprising grid-controlled gaseous discharge devices 3, the control potentials are derived from one phase of the polyphase network 1 associated with the converter anc applied through e single regulating device such as a variable ratio auto-transformer 5, Fig. 1, or a potentiometer 42, Fig. 2, to a phase multiplying circuit providing the required number of phases for the grid circuits. The phase multiplying circuit may comprise a Scott transformer 8, Fig. 1, fed through a phase-splitting circuit comprising a condenser 10 and resistance 11 and feeding the grids either directly as shown or through a further transformer having a delta-connected primary and a three- or six-phase secondary, Figs. 3 and 4 (not shown). Fig. 2 shows an alternative form of phase multiplying circuit comprising a resistance 47 and condenser 46 connected in series across appropriate tappings on the single phase input transformer 44, an artificial neutral for connection to the cathodes being provided by resistances 48, 49. |
