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).
Continued letter discussing the principles and objections to dynamo machines.
| Identifier | ExFiles\Box 35\3\ scan 078 | |
| Date | 2nd March 1925 guessed | |
| EFC1/T. -2- Contd. We agree that the principle of action of the dynamo is good, and that no doubt the results in commutation are very satisfactory, though in our opinion it is really no improvement over the original Trier & Martin 4-brush system, which we have also found to be good in the ways stated. The one objection to either of these two machines is that one cannot conveniently arrange them as real four-pole machines, and it is always easier to get a lower cutting-in speed for the same weight in a four-pole machine. An early cutting-in speed is very desirable when running the machines at 1½ times engine speed. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||