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 comparison data table for various dynamo models.
| Identifier | ExFiles\Box 60\1\ Scan143 | |
| Date | 1st April 1927 | |
| -2- 40/50 C.B. MACHINES. PERFORMANCE COMPARISON OF DYNAMOS. (On routine procedure of 1.4.27) | Dynamo. | (4) Speed for 10V. 14V. 17V. | (5) Speed for O amperes. | Peak Speed. Amperes. | 2500 RPM. amperes. | (6) Speed for 10V. 13.6V. 17V. | (7) Speed for amperes. O.{Mr Oldham} 8 15. | |-------------------|------------------------------|--------------------------|----------------------|--------------------|--------------------------------|---------------------------------| | YH. 15 S.28 | 615 | 615 | 1370, 14.0 | 10.4 | | | | YH. 35 S.28 | 605 | 605 | 1380, 13.5 | 9.8 | | | | XI. 15. SS.{S. Smith} | 610 | 610 | 1415, 14.0 | 9.7 | | | | XI. 35. SS{S. Smith} | - | - | - | - | | | | VK. 55. SS.{S. Smith} X. | 580 | 580 | 1305, 13.4 | 9.4 | | | | XK. 35. SS{S. Smith} | 650 | 650 | 1385, 13.5 | 9.3 | | | | ||