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 page for an electrical machine, detailing performance under various loads.
| Identifier | ExFiles\Box 34\4\ Scan193 | |
| Date | 15th October 1929 guessed | |
| -2- 2. Armature current .95 ampere Field " .64 " Armature current and speed as plain shunt machine with 50 volts on the terminals :- 1. Armature amperes 2.75. Speed 1790 r.p.m. Field amperes .70 2. Armature amperes 3.10. Speed 1815 r.p.m. Field amperes .64 Running on load for 2 1/2 hrs. and developing approx. 1/4 B.H.P. Terminal volts maintained at 50.0 Observations made at the end of the run :- 1. B.H.P. .255 Armature amperes 7.30 Speed 1850 r.p.m. Field " .61 Temperature 80°C. 2. B.H.P. .242 Armature amperes 7.30 Speed 1740 r.p.m. Field " .64 Temperature 18 - 60 - 78. Static torque :- 1. 15.0 lb.in. Field amperes .61 2. 15.23 " " " " .64 Efficiencies :- 1. Electrical efficiency 83.2% Mechanical " 57.9% Overall " 48.1% 2. Electrical efficiency 79.1% Mechanical " 57.5% Overall " 45.5% | ||