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 magnetic circuit of an electrical component.
| Identifier | WestWitteringFiles\J\November1922\ Scan120 | |
| Date | 11th November 1922 guessed | |
| -3- | Part. | Material. | Length (.) | Virtual section sq.ins. | Total flux. | Flux density inch units. | Flux density CM units. B. | H.{Arthur M. Hanbury - Head Complaints} | A.T. per inch. | A.T. | |---|---|---|---|---|---|---|---|---|---| | Armature teeth. | Lamin. Iron. | .60 | .95x.135x3.2 = 1.94 | 223500 | 115,200 | 17,840 | 175 | 354 | 212. | | Armature core. | " | .75 | .9x2x.585 x3.2 = 3.36 | 223500 | 66,600 | 10,330 | 5 | 10 | 8 | | Air gap | Air | .015 | 2.16 x 3.2 = 6.90 | 245000 | 35,500 | 5,500 | 5500 | 11100 | 167 | | Pole core | Lamin. iron. | .75 | .9x1.16x3.2 = 3.17 | 268,000 | 84,500 | 13,100 | 12 | 24 | 18 | | Yoke. | M.S. | 2.15 | 2x.300x5.0 = 3.00 | 268,000 | 89,300 | 13,850 | 17 | 34 | 73 | Total ampere turns required. 478. | ||