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).
Table detailing magnetic circuit calculations for various electrical components.
| Identifier | ExFiles\Box 72\4\ scan0003 | |
| Date | 19th March 1923 guessed | |
| -3- Contd. (vertical text on left margin: -3-) | Part. | Material. | Length (") | Virtual Section sq. ins. | Total Flux. | Flux density (Inch units) | Flux density (Cm. Units) | H.{Arthur M. Hanbury - Head Complaints} | A.T. per inch | A.T. | |-----------------|--------------|------------|--------------------------|-------------|---------------------------|--------------------------|------|---------------|------| | Armature teeth. | Lamin. Iron. | .60 | .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 = 6.76 | 23800 | 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. | ||