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).
Performance specifications for the Lucas E.575T dynamo under various conditions.
| Identifier | ExFiles\Box 36\4\ scan 271 | |
| Date | 26th November 1924 | |
| X 30146 EFG1/T26.11.24. X.9664. EAC.3 DYNAMO. X 30146 The Lucas E.575T machine in the fully hot condition puts up 13.6 volts at 710 r.p.m. At 75°C (our standard temperature for general specification performance, and the normal temperature at which the dynamo may reasonably be assumed to be on a chassis) it is approximately 665 r.p.m. This lower speed, with the present 1.5 gear drive ratio and a normal back axle ratio of 15/52 corresponds to a road cutting in speed of 12.7 m.p.h. N.B. If the cutout is incorrectly set, the actual automatic switching operation may take place later than this. This will not be the fault of the dynamo - it will only mean that a small portion of available charge is cut off. The output of the machine does not rise sharply to its maximum value of 11 amperes, but an output of 10 amps. is reached at 1400 dynamo r.p.m., corresponding to a road speed of 27 m.p.h. in similar circumstances. After reaching its maximum value of 11 amps. the output does not decrease very materially on further increase of speed. EFC. | ||