GB568803A - Improvements in dynamo electric machines - Google Patents

Abstract

568,803. Exciting dynamos. WILLIAMSON, A.. G., and METROPOLITAN-VICKERS ELECTRICAL CO.. Ltd. June 9, 1943, No. 9274. [Class 35] A drooping characteristic generator has the field system divided into one or more pairs of constant flux and variable flux parts angularly spaced and magnetically separated, each part including two polar elements and an upposing series winding is provided on one part in the case of a bi-polar armature winding or on alternate parts in the case of a multi-pole armature winding, whilst the other part or parts of the field system is provided with a constantly excited winding and is without a winding energized by the armature current or by armature voltage derived from the flux in the first part or parts of the field system. In the form shown, the series opposing winding 20 is only on the polar element 3 of part 1 of the core and the interpole 21 and the separately excited coils are on polar elements 6, 7 of part 2 and may also be on polar element 4 of part 5, either as a separate coil 24 or one common to polar elements 4 and 6. The part 1 may be laminated and the part 2 solid, the parts being connected by non-magnetic members including non-magnetic end brackets. The air gaps beneath the poles taper and an interpole may also be provided on part 2. The constant excitation may be derived from a second armature winding connected to a second commutator.