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 and specifications for an actuator box with two coils.
| Identifier | ExFiles\Box 34\3\ Scan056 | |
| Date | 16th June 1939 | |
| -2- contd. (b) Actuator Box with 2 coils in series each of 400# turns of 20 S.W.G. D.S.C. copper. Resistance cold = 1.65 ohms. Current to pull on light = 1.65 amps. Load which, when applied at end of arm, just overcomes friction of motion work = 1 lb.10 ozs. Current when connected to 12 volt battery (coils cold) = 6.25 amps. " Amp turns = 800 x 6.25 = 5000 Maximum load lifted at end of arm (coils cold) = 93 ozs. (5 lbs.13 ozs) Connected in parallel with standard main switch and across terminals of 12 volt battery :- Current through main switch = 1.10, Amp.turns = 1020 " " actuator = 6.20, " " = 4960 Total. 7.30 amps. If push button switch closed slowly, and the load on arm is 75 - 80% of maximum lifted, there is a noticeable lag of the actuator box in pulling on. If the load on arm is 95% of maximum, there is no pull on, if only the carbons of push button close. Contd. | ||