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).
Mathematical comparison of electrical loss between an S. Smith & Sons dynamo and an ordinary dynamo.
| Identifier | ExFiles\Box 3\5\ 05-page087 | |
| Date | 8th August 1919 guessed | |
| The loss y is to be a minimum Therefore equate dy{F R Danby}/dz to zero ∴ 2r[2z - x] = 0 ∴ 4rz = 2rx ∴ 2z = x z = ½ x The loss is therefore a minimum when the current flowing in the resistances is half the output from the armature. Comparison of S. Smith & Sons Dynamo and Ordinary Shunt Dynamo S. Smith & Sons/ Output x amps. If resistance per quadrant = r ohms, Total loss = ¼ x²r + ¼ x²r = ½ x²r watts. Ordinary Dynamo/ Total loss = (¼ x² x 2r) + (¼ x² x 2r) = x²r The loss is therefore twice that in the S.&S. Machine. | ||