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).
Comparative table of specifications for armature windings in S.S. motors.
| Identifier | ExFiles\Box 68\4\ scan0194 | |
| Date | 17th September 1919 | |
| X.1640 TABLE OF ARMATURE WINDINGS ( S.S. MOTORS ) Machine. | R.R.45A. | R.R.17. | R.R. 24 | Lucas Ad.B10. | C.A.V. | Bosch. | Bijur. (6 volt) ---|---|---|---|---|---|---|--- Number of poles (even) (p) | 4 | 4 | 4 | 4 | 4 | 4 | 4 Brush contact area. | 2X.400 | 2X.400 | 2X.400 | 1X.150 | 1X.150 | | 1X.250 Number of slots (S) | 45 | 17 | 24 | 43 | 21 | 41 | 21 Type of winding | Progressive wave. Two circuit. | Retrogressive wave. Two circuit. | Progressive lap. Four circuit. | Retrogressive Wave. Two circuit. | Progressive Wave. Two circuit. | Progressive Wave. Two circuit. | Number of conductors (n¹) | 90 | 102 | 384 | 86 | 84 | 82 | 84 Conductors per slot. (n¹/S) | 2 | 6 | 16 | 2 | 4 | 2 | 4 Coils per slot (c/S) | 1 | 3 | 2 | 1 | 1 | 1 | 1 Number of coils or com. bars. (c) | 45 | 51 | 48 | 43 | 21 | 41 | 21 Turns per coil (n¹/2c) | 1 | 1 | (2 series 4 { 2 par: | 1 | 2 | 1 | 2 Virtual conductors (2c) | 90 | 102 | 96 | 86 | 42 | 82 | 42 Winding pitch in virtual conductors (z) | 23 | 25 | 25 forward 23 backward | 21 | 11 | 21 | 11 Side Text (vertical on right edge): ADAMS AND CO., LTD. (E.38) 12/100 23.11.18 R.R. | ||