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 Ampere Turns for various motor or generator components.
| Identifier | ExFiles\Box 39\2\ Scan033 | |
| Date | 6th December 1920 | |
| -4- 6.12.20. CALCULATION OF AMPERE TURNS. | Part. | Matl. | Length (inches) | Virtual section (sq. ins) | Total flux. | Flux density | H.{Arthur M. Hanbury - Head Complaints} | A.T. per inch. | A.T. | |---|---|---|---|---|---|---|---|---| | | | | | | Inches. | Cm. | | | | Armature teeth. | Lamin. iron. | .360 | 1.015 | 135,000 | 133,000 | 20,600 | 428 | 866 | 312 | | | | .423 | .900 | 135,000 | 150,000 | 23,300 | 932 | 1880 | 798 | | Armature Core. | " | -- | -- | -- | -- | -- | -- | -- | 60 | | Air Gap. | Air. | .015 | 2.31 | 135,000 | 58,500 | 9070 | 9,060 | 18,300 | 274 | | Pole Core. | Lamin. iron. | 1.00 | 2.00 | 162,000 | 81,000 | 12,530 | 15 | 30 | 30 | | Yoke. | Mild steel | 1.75 | 1.50 | 162,000 | 108,000 | 16,750 | 18 | 37 | 65 | | | | | | | | Total | " | 1227 | | | | | | | | | or 741 | | | ||