599,730. Inductor - alternators. BRITISH THOMSON-HOUSTON CO., Ltd., and POHL, R. Nov. 17, 1944, No. 22871. [Class 35] In a high-frequency inductor-alternator in which the stator has an A.C. exciting winding and an A.C. output winding, the excitation frequency being the same as the permeance pulsations due to the rotor teeth, the constant flux component is eliminated by a 90 degrees phase displacement between the excitation current and the permeance 'pulsation. In Fig. 1, the stator tooth pitch is half the rotor tooth pitch. The A.C. excitation winding 3 embraces the stator poles. The output coils 2 are wound -around each stator tooth 1, as shown, and E.M.F's. are induced therein at twice the frequency of the A.C. supply to coils 3; alternatively, coils 2 may be wound around pairs of stator teeth. The A.C. exciter and the alternator may be -mechanically coupled and their rotor teeth may have an adjustable relative angular displacement. Fig. 4 shows a different arrangement of teeth ; each D.C. exciting coil 4 and A.C. coil 3 embraces two stator poles, as shown. The output winding 5 lies in the same slots as winding 4. In this arrangement the exciter is combined with the alternator and the required phase displacement of the exciting A.C. is obtained by capacitive or inductive reactance.