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 of Rotax A.T.12 and other inherently controlled dynamos, with a list of attached documents.
| Identifier | WestWitteringFiles\E\November1920\ Scan53 | |
| Date | 17th November 1920 | |
| To R.{Sir Henry Royce} from EFC. c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to Bn.{W.O. Bentley / Mr Barrington} c. to PN.{Mr Northey} c. to Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} c. EWT. for OY. ORIGINAL EFC1/T17.11.20. X.1005 ROTAX TYPE A.T.12 DYNAMO AND OTHER INHERENTLY CONTROLLED DYNAMOS. Handwritten: X.294, X.295, X.3014b Please find attached in connection with the performances of inherently controlled dynamos the following :- (1) Photostat copy of table of Numerical Particulars of Inherently Controlled Dynamos. (2) Attached to R's copy, blueprints of arrgts. of Magnetic Circuits of C.A.V. N.G.R.R., Lucas E.575, and Smith 2D dynamos. (As regards the first two, we think these may have been sent before, but are sending them again as we are not quite certain of this). (3) Photostat copy of curves of open circuit voltage of Rotax A.T.12 dynamo, which is the main subject of the present report. (4) Photostat copy of Ampere Output Curves of Rotax dynamo for both cold and fully hot conditions. On the same sheet there are also shown average output curves of Lucas E.575 and Smith 2D dynamos in the hot condition with brushes at makers' setting, also for comparison, a curve of specified performance for dynamo for R.R. car. Field current curves of the Rotax dynamo are also given. (5) Photostat diagram of connections of Rotax A.T.12 dynamo. Regarding the Rotax A.T.12 dynamo, we have already mentioned this in our EFC3/T27.9.20. As there stated, the machine is on the whole quite well made and finished. It now appears that the Makers' statements regarding the performance make this appear to be unusually good, owing to the facts :- (1) That they only refer to the early portion of the curve and (2) That they refer to the dynamo in a nearly cold condition. Contd. | ||