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).
Shunt dynamo performance, commutation sparking, and the required change in ammeter type.
| Identifier | ExFiles\Box 60\3\ Scan193 | |
| Date | 3rd March 1933 | |
| -2- Hs{Lord Ernest Hives - Chair}/Wst.1/MA.3.3.33. Cont'd.{John DeLooze - Company Secretary} ready on production there should be no difficulty in obtaining regulators adjusted to suit our conditions. We raised with them the question of the commutation of shunt dynamos at high speeds but as they have done little running above 4500 R.P.M. they were unable to produce evidence of any improvement over the conditions we have been experiencing with our own shunt machine. Preliminary tests shew that our latest shunt machine has considerably less commutation sparking at high speeds than the C.A.V.- Bosch. It is evident that in changing over to vibrator control on our dynamos we shall have to revert to the more expensive moving coil ammeter as it is impossible to read an undamped moving iron ammeter (such as we now fit on the 20/25) when the regulator is in action. The C.A.V. Co. however market a moving coil ammeter which from inspection should not be much more expensive than the moving iron Lucas and we are obtaining quotations and samples for test. Hs{Lord Ernest Hives - Chair}/Wst. | ||