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).
Letter to Messrs. Peto & Radford concerning the output of 20 HP dynamos and their effect on battery life, including photostat curves.
| Identifier | ExFiles\Box 51\1\ Scan215 | |
| Date | 21th August 1923 | |
| X4383 EFC {E. Fowler Clarke - Electrical Engineer} 1/T. 21st August, 1923. Messrs. Peto & Radford, 50, Grosvenor Gardens, London, S.W.1. For the attention of Mr. G.R.N.Minchin. Dear Sirs, Further to our recent correspondence in connection with the output of our 20 HP. dynamos as affecting the life of your batteries, we now send you herewith another photostat curve of the average output of this dynamo at 82°C, a temperature at which it is likely to be working in normal running conditions on the chassis. This shows two curves, one of which is the actual dynamo output, and the other, the amount actually going into the battery, the ignition current having been automatically subtracted on the bench. The setting of the dynamo is in accordance with our very latest specification of production test which we pointed out to you involved a reduction of 1 ampere, under production test conditions, in the peak output, resulting as it does, in slightly more than the reduction of 1 ampere in the actual output curve under chassis conditions. In addition to this we hope shortly to send you a further curve of net output actually taken on the road, but before we can do this we must set one of our experimental | ||