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).
Analysis and performance review of a 6-volt Marmon Delco Dynamo.
| Identifier | Morton\M1.7\ img008 | |
| Date | 28th September 1921 | |
| To R.{Sir Henry Royce} from EFC. c. CJ. & PN.{Mr Northey} c. Ey. & EP.{G. Eric Platford - Chief Quality Engineer} c. Eg. & Da.{Bernard Day - Chassis Design} c. R.R. of America Inc. ORIGINAL X.4402 - MARMON DELCO DYNAMO - 6 VOLT. In accordance with E6/G31.3.21, the dynamo has been removed from the Marmon car and the particulars of this machine obtained. The carcase is made from steel tube. The brush holders are of the radial type, the brushes being bolted to the brush holders in the manner indicated in sketch. (for RV & Da{Bernard Day - Chassis Design}) The material of the brush is soft and resembles H.M.6 Morganite. The armature is hand wound and there appears to be a good deal of unused space at the top of the slots. The commutator looks a good job, but is deeply undercut between the segments. The machine is a 4-pole, single field winding third brush controlled. The output curve is somewhat variable in the later stages, i.e. at the higher speeds, according to the exact position of the control brush bedding on the commutator. The attached photostat gives curves of output starting cold and fully hot respectively, in comparison with our specification of output which, owing to the machine being a 6-volt machine, is shown as double the amperes for any given speed. The operating voltages given on the curves were taken, in error, a little higher than they should have been, which makes the output appear a little better. We could not run the machine at its maximum output continuously without exceeding considerably our limit of 85ºC on the carcase. The maximum ampere output to | ||