From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Specifications for the distribution board and starter motor, including field and armature circuits.
| Identifier | ExFiles\Box 51\2\ Scan164 | |
| Date | 19th November 1923 | |
| Contd. -4- EFC {E. Fowler Clarke - Electrical Engineer} 5/T19.11.23. Distribution Board. All the fuses are of 30 S.W.G. copper (.0124" dia.) except the No.8 emergency fuse which is of three strands of this in parallel. Starter Motor. Carcase dia. 4.500" " length. 4.500" " thickness. .250" Armature dia. 2.85" Active length. 2.500" Weight of complete machine without drive 17.1 lbs. Air gap .015" Field circuit. No. of wound poles 4 No. of turns per coil 5.5 Connection of coils - all in series. Approx. cold (18°C) resistance of field winding .0062 ohms Armature Circuit. No. of armature slots. 29 No. of " conductors 116 No. of coils per slot 1. No. of conductors per slot 4. No. of coils or comm. bars. 29. Step or winding pitch in slots 7 (1 to 8) Size of armature wire .080" ( 14 S.W.G.) Approx. armature resistance cold (18°C). .020 ohms. The motor is a simple series wound four-pole machine with four sets of brushes, the armature being wave wound. Contd. | ||