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 report on motor and generator performance using 'Le Carbone' and 'Hard Corbon' brushes.
| Identifier | ExFiles\Box 34\3\ Scan095 | |
| Date | 15th May 1916 | |
| R R.{Sir Henry Royce} 235 a (400 T) (S.C. 536. 15-5-16) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1546. C O P Y. With "Le Carbone" brushes it was found that the speed of the motor varied considerably on going above 2000 revs. This is due to dust, partially shorting the two brushes to a varying degree, depending on the density of the dust. The brushes I am at present using are a little too hard marking the commutator but I get steady readings. - - - - - - - - - - - - - - - - - - - - - - - - In the test both motor and gemerator separately excited both armatures had 45 slots wave wound and standard field coils and had direct coupled drive. (Not Standard Brushes). Hard Corbon Brushes used. MOTOR GENERATOR Field Armature Field Excitation Excitation Amps. Amps. Volts. Amps. E.M.F. Speed. 26 31 11 40 12 3000 25 32 11 45 13 3000 25 34 11 50 13.5 3000 24 35 11 55 14 3000 24 38 11 60 14.5 3000 | ||