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).
Comparison of Smith, Lucas, C.A.V., and Rotax dynamos and their respective cutouts.
| Identifier | ExFiles\Box 36\4\ scan 205 | |
| Date | 21th April 1921 | |
| Contd. -5- EFC4/T21.4.21. cutouts we know. If the Smith dynamo were standardised no doubt the Smith cutout would be standardised with it. Quoted price of the Smith cutout £1.13.9 Quoted price of the Lucas cutout 12.6d., but this does not include the case and terminals which would be required if it were used like the Smith, as an independent unit. The Lucas cutout is somewhat erratic in operation and liable to failure. The Smith cutout is definite in operation and has given consistently satisfactory service on the experimental cars. Weight of Smith cutout, 23½ ozs. " " Lucas " (without case and terminals) 9 ozs. As regards the heating of the Lucas and Smith dynamos, there is not much to choose, but the slight difference is in favour of the Smith. C.A.V. N.G.R.R. Dynamo. This dynamo has already been referred to. We understand that from pre-War experience we gained a favourable impression of this machine. The carcase, however, is not circular. For this and other reasons such as post-War experience of these machines, they are not considered suitable for standard on the R.R. car. The single price is £17.17.6 and the weight 36½ lbs. Rotax A.T.12 Dynamo. A sample model of this machine, in which Mr. Royce has shown considerable interest, has been experimented with recently on the bench. The point about this machine is that it appears to be absolutely silent, partly due, as R.{Sir Henry Royce} contends, to the fact that it is made with an even number of armature slots, making use of two coils per slot and a dummy. The weight of the dynamo is 27 lbs. Single price - £13.10.0. Carcase dia. and length, 5.75" by 4.40" Armature dia. and active length 3.745" by 3.20" The principle of operation of the machine is that of the single field winding third brush control, and is the simplest form of inherent regulation possible. Contd. | ||