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).
Test results for a sequence starter, focusing on armature pull and current characteristics of different windings.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan001 | |
| Date | 1st October 1926 | |
| To R.{Sir Henry Royce} from EFC. c.c. RJ. AJS. EFC2/T1.10.26 ORIGINAL SEQUENCE STARTER. x7650 We have now completed the tests asked for in your RL/M22.9.26. and attached please find a photostat copy of curves giving the law of variation of lbs. weight pull on the armature to the distance of the armature out from its datum position. There are full line curves for the w teazer (plus main) winding, and dotted line curves for the main winding only, but in neither case did the current pass through the armature, as this would have made it not only inconvenient but uncertain in measurement owing to the frictional effect introduced in neutralising the torque produced. I do not think that the effective longitudinal pull on the armature should be greatly affected by the flow of current through the armature. You will see that in no case has the curve risen to its maximum at a distance of 1.250" out - that would appear to be as we wish it. As regards the actual current that may be expected to be used, the actuator current on the present system on 9-EX with the present actuator box in series, is about 20 amperes. This would increase to just over 27 amperes were the actuator box excluded from the circuit. That is for 17-SWG. winding; The number of turns of which is 30 on the particular motor tested. If we revert to the 16-SWG winding, the corresponding current would be approximately 14 amperes, | ||