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).
Comparison table of specifications for various dynamo machines.
| Identifier | ExFiles\Box 36\4\ scan 003 | |
| Date | 13th April 1920 | |
| Top annotations: X.3014 (underlined) X.294. DYNAMO TABLES. X.3014 / X.295 X.3538. Table: | Machine. | C.A.V. N.G.H.H. | Lucas E.575. | Lucas A.400 | Bijur. | Liberty. | Smith T & M 3A. | Smith T & M A.{Mr Adams} | Smith T & M 2U. | R.R. 20 HP. | |---|---|---|---|---|---|---|---|---|---| | Number of Poles(even) (p) | 2 | 2 | 4 | 4 | 4 | 2 | 2 | 2 | 4 | | Number of slots (s) | 24 | 30 | 43 | 15 | 21 | 19 | 19 | 19 | 17 | | Type of winding. | Prog. lap. | | | | | Retrog. lap. | Retrog. lap. | | Retrog. wave. | | Number of conductors (n') | 672 | | | | | 760 | 760 | | 408 | | Conductors per slot (n'/s) | 28 | | | | | 40 | 40 | | 24 | | Coils per slot (c/s) | 2 | 1 | | 3 | 1 | 2 | 2 | 2 | 3 | | No. of coils & com. bars. (c) | 48 | 30 | 43 | 45 | 21 | 38 | 38 | 38 | 51 | | Turns per coil. (n'/2c) | 7 | | | | | 10 | 10 | 10 | 4 | | Virtual conductors (2c) | 96 | | | | | 76 | 76 | 76 | 102 | | Winding pitch in virtual conduc: (z) | 49 for'd 47 back'd | | | | | 33 for'd 35 back'd | 33 for'd 35 back'd | | 25 R | | Step Winding pitch in slots. | 12 | | | | | 8 | 8 | 8 | 12 | Right margin text (vertical): R.R. Co 50 TD 81 5M 6-19 C 262 | ||