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 components like the armature, pole core, and yoke.
| Identifier | WestWitteringFiles\J\March1923\ Scan31 | |
| Date | 11th January 1933 guessed | |
| -3- Contd. Part. Material. Length (") Virtual section sq.ins. Total Flux. Flux density Inch units. Cm. units. B. H.{Arthur M. Hanbury - Head Complaints} A.T. per inch A.T. Contd. -3- Armature teeth. Lamin. Iron. .80 .9x5x.130 x3.2 = 1.87 218000 116,500 18,100 185 374 224 Armature core. " .75 .9x2x.585 x 3.25 = 3.42 218000 63,800 9900 5 10 8 Air gap. Air. .015 2.08x3.25 = 6.75 238000 35,300 5450 5450 11000 165 Pole core. Lamin. Iron. .67 .9x1.10x 3.25 = 3.22 261000 81,100 12600 12 24 16 Yoke. M.S. 2.08 2x.312x 5.5 = 3.43 261000 76,100 11,800 14 28 43 Total ampere turns required 456 ======== Contd. | ||