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).
Plan showing the dimensions and calculations for a transformer's iron core, primary, and secondary windings.
| Identifier | ExFiles\Box 32\4\ Scan002 | |
| Date | 19th August 1919 guessed | |
| X.1581 Plan showing dimensions of iron, primary & secondary windings - Transformer - (used on = 220/45v.) Top Diagram Dimensions: 3.81 cms 2.54 cms 3.49 cms 5.08 cms 14.15 cms 1.44 1.24 1.43 .35 Left Diagram Dimensions: 16.51 cms (11.43)(10) cms Bottom Left: Gross C.S. Area of core 3.00 sq inches. Calculations: Primary Length of mean turn = 22.35 cms Gauge = 23. (D.C.C.) Length of Primary wire = 22.35 x 1390 = 31,100 cms. = 12,250 inches = 1022 feet. Resistance at 15°C = .01763 x 1022 = 18.0 ohms. * Ohmic Drop at no load = 18.0 x .035 = .63 Secondary Length of mean turn = 30.8 cms Length of secondary wire = 30.8 x 2980 = 91,750 cms = 36,100 inches = 3010 feet Gauge = 28 (DCC) Resistance at 60°F = .04636 x 3010 = 140.0 ohms. | ||