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).
The performance and efficiency tests of two 50-volt motors.
| Identifier | ExFiles\Box 34\4\ Scan230 | |
| Date | 29th August 1932 | |
| X2048 To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Wst. c. Hy.{Tom Haldenby - Plant Engineer} Hs{Lord Ernest Hives - Chair}/Wst.1/AD29.8.32. 50-VOLT MOTORS The two motors which Hs.{Lord Ernest Hives - Chair} is bringing down to you today have been tested and we find that they give a much better efficiency than the two previous motors you had. The average figures taken on our brake test are as follows :- Developing .4 B.H.P. the speed was 2110, armature current 10.65 amperes field current .75 amperes making a total of 11.4 amperes This gives an efficiency of .52 overall. This compares most favourably with an efficiency of .45 at a much lower torque rating obtained with the previous motors. This is probably due to the fact that these machines have a much better armature circuit than the two which you have had previously. We have left the field and armature terminals completely insulated in order that we can arrange these at will for either direction of rotation. The brushes are set dead neutral and we have observed that when running either rotation very little sparking occurs. Hs{Lord Ernest Hives - Chair}/Wst. | ||