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).
Diagnosis of a vehicle's dynamo and lighting system failure, identifying three potential causes and concluding the dynamo itself is at fault.
| Identifier | ExFiles\Box 61\2\ scan0067 | |
| Date | 26th August 1913 guessed | |
| -2- Wor{Arthur Wormald - General Works Manager}/SM6/L18613 Contd. your demands. If, on the other hand, you for some reason use the car for several long night runs and not at all during the day time, you would then have insufficient current to fully illuminate the lamps. We would point out, however, that this would not react adversely on the dynamo, but the battery is liable to suffer, the visible result being the dimness of the lamps which might be remedied by switching one/light off or using say 32 c.p. lamps. You will therefore see that on this system it is essential to do a slightly larger proportion of day running with the dynamo charging than night running with lamps on. The failure of your armature we can only put down to one of three causes.- (1) The free-wheel sticking. (2) A short on the armature. (3) A short in the wiring system. No.1 is a very frequent source of trouble, the cause usually being insufficient lubrication. We examined your free-wheel but it appeared to be in perfect condition. The wiring system we also tested and it appeared to us to be in good order. This would point to the fact that the fault lies in the dynamo itself, and we have asked the makers to issue a report, which so far we have not yet received, the contents of which will be forwarded to you in due course. We trust that we have explained this matter to your satisfaction. | ||