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 points on dynamos, armature reluctance, and headlamp bulb wattage.
| Identifier | ExFiles\Box 163\6\ img132 | |
| Date | 21th January 1931 | |
| HARD FINDINGS FCL/ADSO.1.31 contd. -2- With regard to the second portion of your remark, for instance "The possibility of maintaining the rate of charge with speed by using another position of 3rd. brush. Probably no advantage in my suggestion but I should like it examined" this is thoroughly covered by the work at present in progress to improve the performance generally, the hopeful solution of the problem being the introduction of the additional reluctance into the armature teeth. With regard to item 2. of E's note E1/M10.1.31 we are of the definite opinion that this is an advantage and further it was our (and we think E's) impression that you definitely advocated this in your R1/M3.12.30 by your remark "it only seems important to reduce the current if this is too heavy for the battery when no lighting is used" We feel confident, and I think E.{Mr Elliott - Chief Engineer} will agree, that we have advocated the best scheme for immediate production. The complete arrangement found its first expression on Sg{Arthur F. Sidgreaves - MD}'s car 58-CN{Mr Chamberain} and Sg.{Arthur F. Sidgreaves - MD} reported in his Sg{Arthur F. Sidgreaves - MD}8/E21.1.31 addressed to Wor.{Arthur Wormald - General Works Manager} that "the output of the dynamo as rearranged on 58-CN{Mr Chamberain} now seems very good under all conditions". With regard to item 3. of E's note, the relatively small effect of this on the output curve is shown by the change from Curve IV. to Curve V.{VIENNA} With regard to item 4. of E's note, this would appear to be the least approved proposal, Sg.{Arthur F. Sidgreaves - MD} remarking in his Sg{Arthur F. Sidgreaves - MD}8/E21.1.31 :- "With regard to the substitution of 48 watt headlamp bulbs instead of 60. I asked PN.{Mr Northey} to take the car out specially with a view to testing the illuminating power of these less watt lamp bulbs. He informs me that the tests made were not altogether satisfactory and that he does not consider that they give sufficient light for a man who wanted to drive at high speed on a dark night. We, however, see no objection to the 48 watt bulb being standardised when the modified dynamos begin to come through so long as it is clearly understood that, once a car is delivered, we cannot control the matter. | ||