| 摘要 |
892,159. Control of D.C. motors. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. July 12, 1960 [July 13, 1959], No. 23988/59. Class 38 (3). During the initial rheostatic braking of D.C. traction motors 1 . . . 4 the field windings F3, F4 of at least one motor group are boosted from a D.C. source connected between terminal A and earth. During running the motors may be connected in series or in two parallel groups, each group having series resistors R1, R2, R3, R4 and divertor resistors SR1, SR2. The boosting current flows through F3 and F4 to earth at the mid-point of R3, divertor SR2 being blocked by a rectifier RX. When the normal field current has built up sufficiently the boosting current is interrupted at TA. J1, J2 and J3, J4 are reversing contactors. In an alternative arrangement the fields of both motor groups may be boosted. Specification 885,895 is referred to. |
