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 test results and physical specifications of a machine compared to its design specification.
| Identifier | WestWitteringFiles\G\September1921\ Scan80 | |
| Date | 21th September 1921 | |
| -2- Contd. The specified curve is also shown dotted for comparison. In the fully hot condition, an open circuit voltage of 13.6 is attained at 600 R.P.M. - our specification gave 640 R.P.M. In the cold condition, the voltage of 12.4 is attained at a speed of 500 R.P.M., our specification corresponding to 540, thus the machine cuts in a little earlier than our specification. Owing to the rise of output not being quite so rapid as that which we call for, the output curve does not quite comply with the specification in the middle stages. The carcase diameter is, of course, 5" and the weight of the dynamo,inclusive of pulley but exclusive of suspension, is 22 lbs. 2 ozs, our suggested limit being 25 lbs. The armature winding of this machine is entirely similar to that of the AT.12, of which a diagram was sent to you showing the method of connecting up the odd coil. The armature diameter is 2.75", active length 3.40". Carcase length 5.00". The brush gear is entirely similar to that of the AT.12 which you have at N.Wittering. The material of the brushes is C.4. Morganite. On the heating test of this machine, we found that, running the machine at maximum ampere output with the makers setting of the control brush (which we afterwards confirmed to be the best setting for maximum output for a given heating), the final carcase temperature was only 78°C. Contd. | ||