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).
Description of the various output curves for a 20 HP dynamo.
| Identifier | ExFiles\Box 165\6\ img239 | |
| Date | 14th December 1923 | |
| -6- The curves shown on the blue print for 20 HP. comprise :- Firstly, our original specified curve of output requirements of 20 HP. dynamo. Secondly, the representative output curve of present standard 56 coil 28 slot 20 HP. dynamo. Thirdly, the output curve of a higher output dynamo such as has been supplied to customers in one or two instances. and Fourthly, the output curve of the first experimental intermediate output machine. All these curves are taken (as all dynamo output curves are now taken) at one dynamo temperature (of 80°C.) indicated in our usual way. N.B. We do not allow the heating effect of the field and armature current materially to upset the condition that output curves are observed with the dynamo thermometer reading 80°C. In this case of the higher output and intermediate output, these curves are output curves of the dynamos with control brush settings such as to give a maximum rise of temperature when running on the peak specified in a certain well defined way. We take considerable care to make the curves which we reproduce as nearly as possible properly comparable. | ||