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).
Conversion of 50-volt motors for a 25-volt lighting system by altering the field windings.
| Identifier | ExFiles\Box 34\4\ Scan196 | |
| Date | 28th October 1929 | |
| X.2048. To R.{Sir Henry Royce} from EFC. EFC2/AD28.10.29. 50 VOLT MOTORS I have seen Mr.Minchin recently and he tells me that he believes it is now your intention to retain your 25 volt lighting, with the addition of two more cells. I am quite in agreement with his suggestion that 14 cells is the right number for 25 volt lighting, and satisfactory lighting can thus be obtained at this voltage unless the conductors are too small. Provided the slower speed and smaller power would suit your purposes, we could alter the field windings of the two motors sent, to make these suitable for 25 volts, by half paralleling the field windings. We would suggest however, for certain reasons, that the motors may not be found to be very wrong for 28 volts in their present condition. EFC. | ||