Improvements in and relating to electric converting circuits

1,000,258. Converting. LICENTIA PATENTVERWALTUNGS-G.m.b.H. Sept. 28, 1961, No. 34902/61. Heading H2F. An electric converter arrangement has at least two series connected sections, each comprising a secondary transformer winding 4, 5, in series with a device 7, 8, 9 whose current flow is controlled in time relation to the voltage in winding 4, 5, 6, a unidirectional by-pass device 13, 14, 15 being connected in parallel to each of the sections. The transformer primary windings 1, 2, 3 are delta connected to the A.C. terminals and the sections are in series with a saturable or other choke 12 across D.C. terminals 10, 11. Devices 7, 8, 9 may be controlled mechanical contacts, a multiple segment rotating device of the commutator kind, or diodes in series with transductors, or with controlled mechanical contacts (Fig. 2, not shown,) or semi-conductor devices, or mercury jets. The output voltage is regulated by controlling the periods when the sections are conducting, or by keeping the lengths of their conducting periods fixed and controlling their phase relationship. Instead of a three-phase transformer primary winding, a single-phase transformer winding may be used (Fig. 2, not shown). For inverting or frequency changing the conducting periods of the by-pass devices 13, 14, 15 are controlled.