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).
Calculation table for the ampere-turns required to produce the necessary magnetic flux in a component.
| Identifier | WestWitteringFiles\Q\2April1927-June1927\ 202 | |
| Date | 31th March 1927 guessed | |
| -6- AMPERE TURNS NECESSARY TO PRODUCE FLUX REQUIRED. | Part. | Matl. | Length (") | Virtual section (sq. ins) | Total Flux. | Flux density | H.{Arthur M. Hanbury - Head Complaints} | AT. per inch. | A.T. | |---|---|---|---|---|---|---|---|---| | | | | | | Inch. units. | Cm. Units. | | | | | Armature teeth. | Lamin. Iron. | .360 | 7.5x.092 x 2.75 = 1.90 | 194000 | 102000 | 15800 | 50 | 100 | 36 | | Armature core. | " | .650 | 2 x .550 x 2.75 = 3.03 | 194000 | 64000 | 9900 | 5 | 10 | 7 | | Air gap. | Air. | .0125 | 1.80x2.75 = 4.95 | 194000 | 39200 | 6070 | 6070 | 12140 | 152 | | Pole core. | M.S. | .625 | .9 x 2.400 = 2.16 | 233000 | 108000 | 16700 | 100 | 200 | 125 | | Yoke. | M.S. | 1.700 | 2 x .3125 x4.000 = 2.50 | 233000 | 93300 | 14500 | 25 | 50 | 85 | | | | | | | | Total | = | 405 | Contd. | ||