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).
Dynamo and battery charging issues, with proposed modifications for different customer usage patterns.
| Identifier | ExFiles\Box 168a\4\ img063 | |
| Date | 9th March 1938 | |
| 6144 BY.5/G.9.3.38. [REDACTED] Childe Let me have a record of the running done by the new armature. ELECTRICAL SYSTEM. Do we recommend 1/2 engine speed with the new dynamo? Pam (1). PHANTOM III. (a). As a result of a considerable amount of work which has been done since the complaints were raised during the winter months in connection with discharged batteries, we have demonstrated that for existing dynamos we are limited to the amount of current which can be taken out of the machine, otherwise at high speeds at night the dynamo will burn out as a result of excessive sparking. In order, however, to overcome as far as possible the difficulties of our customers without going to a new armature, we have developed in conjunction with the C.A.V. a regulator of the present type which is modified only by setting the regulator in question to give an average of 18 amps. This should enable customers domiciled in London, who get a reasonable amount of daylight running, to keep their batteries in good condition, but at the same time we feel it is necessary under the very adverse circumstances which obtain in London that we must recommend customers who are working continuously in London, with little country running, to use a trickle charge off the mains, the charge in question should be in the neighbourhood of 5 amps. (b). For customers who are doing a fair amount of daylight running, we think the use of the modified regulator and 48 watt bulbs in the headlamps, as already specified, will overcome 95% of this particular type of complaint. For the odd customer who runs at night, with very little daylight work, we would have to supply a modified dynamo having a greater number of commutator bars and less turns per slot to the armature in conjunction with a regulator with 2 1/2 series turns. We should not make a recommendation to change the dynamo until we were certain that the regulator only with the higher setting was insufficient. | ||