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 showing starter motor resistance estimations at various loads for the 'K' motor.
| Identifier | ExFiles\Box 64\1\ scan0308 | |
| Date | 7th September 1928 | |
| STARTER MOTOR RESISTANCE ESTIMATION AT VARIOUS LOADS. Date:- 7 Sept 1928 Motor:- K Back E.M.F./speed = .01184 torque/current | Current (amperes) (C) | Conductor Torque (lb-ins.) (T) | Back E.M.F / speed | Speed on brake (R.P.M.) (N) | Back E.M.F (volts) (Es) | Impressed E.M.F. (volts) (E) | Ohmic Volt loss | Motor resistance (ohms) | |---|---|---|---|---|---|---|---| | 20 | - | - | - | - | 11.60 | - | - | | 30 | - | - | - | - | 11.40 | - | - | | 40 | 10.5 | .00311 | 3110 | 9.67 | 11.20 | 1.53 | .0382 | | 50 | 14.5 | .00344 | 2660 | 9.15 | 11.00 | 1.85 | .0370 | | 60 | 19.0 | .00375 | 2330 | 8.74 | 10.80 | 2.06 | .0344 | | 80 | 29.0 | .00429 | 1810 | 7.77 | 10.40 | 2.63 | .0329 | | 100 | 39.0 | .00462 | 1460 | 6.75 | 10.00 | 3.25 | .0325 | | 120 | 50.0 | .00493 | 1180 | 5.82 | 9.60 | 3.78 | .0315 | | 140 | 61.5 | .00520 | 940 | 4.89 | 9.20 | 4.31 | .0308 | | 160 | 73.0 | .00540 | 700 | 3.78 | 8.80 | 5.02 | .0314 | | 180 | 85.0 | .00559 | 505 | 2.825 | 8.40 | 5.675 | .0315 | | 200 | 97.0 | .00574 | 310 | 1.78 | 8.00 | 6.22 | .0311 | | 220 | 108.5 | .00584 | 110 | 0.64 | 7.60 | 6.96 | .0316 | | 240 | - | - | - | - | 7.20 | - | - | | 260 | - | - | - | - | 6.80 | - | - | Handwritten note: .0316. Direct observations of resistances at 20°C. Field winding = .0130 ohm. } .0268 Armature " = .0138 ohm. Total motor resistance at 200 amperes = .0360 ohm. Brushes 9° advanced 7.9.28. EFC. | ||