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).
Test results for a dynamo's open-circuit volts and ampere-output under specific conditions.
| Identifier | ExFiles\Box 59\1\ Scan153 | |
| Date | 29th June 1920 | |
| ROLLS-ROYCE LTD. INSTRUCTIONS. RR 238 (150 BKS.) (SH57. 29-6-20.) MP 224355 19 To Order No. Customer's No. S this setting up vibration. Thus if a large resistance be used, the falling back voltage must be very low, and the head-lamp series winding on the controller will need to be correspondingly fine. Note. The dynamo operation at 80°c and having the 16.5 w added to the field circuit was observed as follows:- OPEN-CIRCUIT VOLTS. Volts | 10.0 | 12.0 | 14.0 | 15.0 | 17.0 Speed | 2500 | 2650 | 2750 | 2800 | 2900 AMPERE-OUTPUT (SCHEDULED VOLTS) Amperes | 0 | 0.5 | 0.6 | 0 Speed | 2700 | 3200 | 3600 | 3800 Signed Y.R. This Sheet must be filed on completion of the work. | ||