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).
Correcting previously supplied wire sizes for the EAC silent starter scheme.
| Identifier | ExFiles\Box 64\3\ scan0175 | |
| Date | 17th June 1924 | |
| X8650 SECRET To RY/RD. from EFC. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. EFC3/T17.6.24. X.9650 - EAC. SILENT STARTER. We regret that in fixing up with you the sizes of the wire for the main switch and hold-off relay units of the EAC. silent starter scheme, we inadvertently gave you the wrong sizes of wire, on account of considering these as being similar to the present 40/50 main switch of the series connected type, whereas it should have been considered similar to the old 40/50 main switch of the parallel connected type. Thus the sizes of wire which we should have arranged with you should have been :- For the main switch unit, 26 S.W.G. (as for the second 40/50 parallel connected main switch of increased power). For the hold-off coil, one even gauge less coarse wire than in the case of the main switch, viz. 28 S.W.G. Will you kindly have the windings run out again on these new lines and let me know the number of turns and length of mean turn, corrected as above, (more particularly of the main switch in the first instance), and we will then settle the size of resistance to go in parallel with the main switch unit winding as soon as possible afterwards. EFC. | ||