GB190319520A - Improvements relating to Systems for Controlling Alternating Current Motors - Google Patents

Abstract

19,520. Scott, C. F. Sept. 13, A.D. 1902, [date applied for under Patents Act, A.D. 1901]. Motors, controlling. -Relates to the operation of single-phase alternating - current motors in which a series relation or its equivalent is maintained between the armature and the field, the object being to supply a different amount of current to the armature from that supplied to the field while yet being able to vary the different currents proportionately for controlling purposes as though they were in simple series connection. Series transformers are provided for supplying the armature and field, or either, in any desired relative proportion, the current in the primary being varied for control purposes. Fig. 1 shows one arrangement as applied to a railway vehicle. The armature 7 is connected in series with the secondary 8 of a transformer 9, and the field 10 with the secondary 11 of a transformer 12. The primaries 13, 15 are in series with the secondary of a regulating- transformer 5, the primary of which is connected to any suitable source. Instead of separate transformers 9, 12, an auto-transformer 17, Fig. 3, may be employed, and also a regulating auto-transformer 18. The arrangements may be applied to two or more motors connected in series or in parallel.