| 摘要 |
395,036. Master control of D.C. motors. BROOKS, R., Ivyhurst, Charlton Drive, Sale, Cheshire, FERGUSON, A. D. Ardriac, Ashton Lane, Ashton-on-Mersey, and ASSOCIATED ELECTRICAL INDUSTRIES, Ltd., Crown House, Aldwych, London. Jan. 13, 1932, No. 1064. [Class 38 (iii).] Motors 1 .. 4 are accelerated by armature resistances, through series - parallel stages, under the control of a master controller, and two current limiting relays OCA, OCB, one for each leg of the parallel motor circuit, the relay OCB being ineffective during the series acceleration. The setting of the relay OCA is changed for parallel operation to be lower than the setting of the relay OCB which in turn is lower than that of the relay OCA when the motors are in series. The change in the setting of the relay OCA may be effected by an additional opposing coil connected in shunt or in series with the operating coil of the switch JR and, therefore, energized only until the switch JR is opened at the end of the series acceleration. Alternatively the additional coil may assist the main coil and may be energized through parallel normally open contacts on the switches J and G when these switches close at the end of the series acceleration. In another arrangement two additional assisting coils are provided connected respectively across the operating coils of the switches J and G. |
