Improved method of controlling the field strengths of series-wound motors

摘要

496,394. Control of D.C. motors. TUSTIN, A. May 31, 1937, No. 15016. [Class 38 (iii)] [Also in Group XXXV] A four-pole series motor with a wave wound armature has four coils,one per pole, series connected to give a weak field,these being series connected with a second set of coils comprising a second coil on each pole directly connected to a coil on an adjacent pole to give the highest field strength, an intermediate field strength being obtainable by utilizing the four weak field coils in series with half the other set. In the form shown, each pole has two coils as shown and when terminals 10, 11 are used the four weak field coils 2-5 alone are effective while terminals 10, 12 give the eight coils in series. An intermediate excitation is obtained by using terminals 10, 13 which connect two additional coils 8, 9 in series with the weak field coils. Further intermediate stages may be obtained by utilizing terminals 10, 12 with a resistance in parallel with coils 6 and 7 and by using terminals 10, 13 with a resistance in parallel with coils 8, 9.