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).
Specification table for a testing transformer, detailing winding sections and voltages.
| Identifier | ExFiles\Box 32\4\ Scan058 | |
| Date | 8th February 1926 | |
| X1581 B.2.26. TESTING TRANSFORMER. Section. | No. of turns. | Arrgt. of winding. | S.W.G. | Nominal voltage. A | .2, 1, 2 | Starter motor Bar 2 in parallel. | | 1.6, .8, 1.6, 4.0 B | 5, 10 | 3 in parallel. | 13¼ | 4, 8, 16.0 C | 20, 40 | 2 in parallel. | 13¼ | 16, 32, 64 D | 5, 10 | 2 in parallel. | 13¼ | 4, 8, 76 E | 80, 160 | | 13¼ | 64, 128, 268 Total 335 | | | 268 | ||