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 sheet for a 16:1 ratio sequence starter motor.
| Identifier | ExFiles\Box 64\2\ scan0164 | |
| Date | 30th June 1928 | |
| X7625 30.6.28. 16 : 1 RATIO SEQUENCE STARTER MOTOR. CALCULATION QUANTITIES. (See EFC5/T22.6.27) Torque on conductors = 90 lb-inches. Speed of " = 640 r.p.m. Power converted = .00001587 x 90 x 640 = .915 H.P. = 683 watts. Assumed electrical efficiency = .452 Watts supplied = 1510. or 180 amperes at 8.40 volts. Power converted corresponds to 180 amperes at .452 x 8.40 = 3.80 volts. ØZ = (60 x 10^8 x 2 x 3.80) / (640 x 4) = 17.73 x 10^6 (by back E.M.F. and speed) or = (108 x 2 x 90) / (1.41 x 4 x 180) = same figure (by amperes and torque) Contd. | ||