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).
Extract from G.W. Hancock's report comparing the output of dynamos on 18-GIV and 19-GIV models.
| Identifier | ExFiles\Box 62\3\ scan0251 | |
| Date | 16th November 1931 | |
| X6005. Extract from G.W.Hancock's report dated 16.11.31. RE : DYNAMO ON 18-GIV. The dynamo on 18-GIV apparently has not been brought up-to-date - it will not maintain the battery charge. In comparison with the dynamo fitted to 19-GIV the following are the differences in the output. 18-GIV half charge dynamo just balances at 19 M.P.H. at 30 M.P.H. the output is 4.4 ampers, at 40 MPH. 5 amps. 60 M.P.H. 6 amps. and at 70 M.P.H. 5 amps; whereas with the dynamo fitted to 19-GIV, the dynamo balanced at 16 M.P.H., at 20 M.P.H. the output was 3.5 amps., at 30 M.P.H. 7.5 amps., at 40 M.P.H. 7.5 amps., at 50 M.P.H. 7.5 amps. and at 60 M.P.H. 7.0 amps. It will be seen therefore, that we are definitely down with the output with 18-GIV dynamo. Can Wst. give any explanation for this. We shall in the meantime endeavour to increase the output by pushing the control brush forward as we cannot carry on. We are aware that we are using 60 watt headlamp bulbs, but this does not in any way interfere with the half charge output. | ||