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).
Two-rate charge scheme and comparing output curves for different dynamo modifications.
| Identifier | ExFiles\Box 163\6\ img131 | |
| Date | 30th January 1931 | |
| X6016 To R.{Sir Henry Royce} from EFC. c. Sg.{Arthur F. Sidgreaves - MD} c. E.{Mr Elliott - Chief Engineer} PN.{Mr Northey} EFC1/AD30.1.31. X.6016. TWO-RATE CHARGE SCHEME. X.6004. Xx6006. With reference to your remark on the recently circulated standardisation sheet for the switchbox for full rate of charge in the S & T as well as in the H S & T position, for instance "Personally I do not think this scheme worth the cost and complication. I cannot see exactly how it saves the dynamo difficulty to make any practical difference". E's memo E1/M10.1.31 addressed to you, gave as 1, 2, 3 and 4 the four items which it was considered should be included on immediate production. With regard to item 1, on E's memo perhaps we should make it clear that this implies a reversion to the 48 coil medium output dynamo without pole piece modification in place of the 48 coil high output dynamo with pole modification originally put forward for the two-rate charge scheme. The output curves for the two cases are shown respectively as the higher curve on blue print 40/50 2. and curve No.III on blue print 40/50 1. issued under cover of our EFC3/AD9.1.31. For your convenience of reference we now attach further sheets 40/50 2. with curve No. III from 40/50 1. drawn on so that the relative outputs of the two machines can be readily compared. III. Is the output curve for the 48 coil machine with pole modification as originally suggested for the two-rate charge scheme. (allowed temperature rise setting 62C°). IV. Is the output curve for the 48 coil medium output machine xx later arrived at between E.{Mr Elliott - Chief Engineer} and my self as more suitable for this performance and for which a standardisation sheet has been circulated. (allowed temperature rise setting 65C°). | ||