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).
Technical letter detailing dynamo voltage regulations for a Bentley car and addressing experiences with Bosch Dynamos.
| Identifier | ExFiles\Box 60\4\ Scan143 | |
| Date | 27th February 1932 | |
| -2- Messrs. Rolls-Royce Limited. 27th February, 1932. a Bentley car, they should be as follows:- Cut-in voltage ..... 12/17 v.{VIENNA} Regulation without load. = 14.3 v.{VIENNA} - 16.8 v.{VIENNA} Regulation with 100 watt resistance load = 12.9 v.{VIENNA} - 14.1 v.{VIENNA} Return Current - 3 - 6.5 Amps. We trust that this information is what you require. With regard to your remarks that you understood that Mr. W. Iden had had trouble with his Bosch Constant Voltage Dynamo fitted to his Rolls-Royce car, the writer made a point of investigating this on his return to London. He telephoned Mr. Clark and learned that at no time has the Bosch Dynamo fitted to Mr. Walter Iden's Rolls-Royce car given the slightest trouble, and in fact Mr. Clark stated that this Dynamo has worked perfectly. It is true that this car was taken to Bosch Limited Works for the electrical system to be examined, and it was found that the Battery was defective, this was attended to and the Dynamo Battery system has worked perfectly ever since. Furthermore, Mr. Clark stated that Mr. Morison, the Chief Engineer of the National Omnibus Company has had fitted to his own car for over three years a Bosch Constant Voltage Dynamo, and that it is a fact that this Dynamo has functioned perfectly during the whole of this time; and that the Dynamo has in no way been attended to, not even the commutator cover has been removed to examine, to see if the brushes require renewing. In fact, Mr. Clark emphasizes that this Dynamo has not been looked at since it was fitted. As a matter of fact this experience is consistent with our experience of Bosch Dynamos to which we have fitted to motor-cars in this country. On the 6½ and later 8 litre Bentley cars, the writer is unaware that one of these has been returned to us in any way for service. This also applies to the Axial type Starter which was fitted as standard to the 6½ and later 8 litre Bentley cars. If we can be of any service to you, we shall always | ||