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).
Extract detailing experiments on an actuator box with increased power for a parallel arrangement.
| Identifier | ExFiles\Box 172\3\ img012 | |
| Date | 23th December 1919 | |
| R.R. 283 A (100 T) (S.F. 80) 6.S-19. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 7469 Extract from Ck{Mr Clark}9/T23.12.19. X.3748 - ACTUATOR BOX OF INCREASED POWER FOR PARALLEL ARRANGEMENT. Although we have not had an actuator box with this winding in operation on a car, there is no doubt of the increased efficiency of this arrangement, as we have made a thorough set of comparative experiments on the bench between the combination of this box with the standard main switch, and the combination of standard actuator box and main switch. We set up, for instance, two actuator boxes side by side on the bench, each loaded up to the same amount representative as nearly as possible of the actual load met with on the car, and further the load was suspended in each case in a bath of oil so as to imitate a viscous resistance. It was patently [manifest] obvious from these experiments that the magnetic circuit of the standard actuator box is not made full use of. With the standard combination, for instance, there was quite a definite time lag of about one-third of a second between the coming on of the main switch and the actuator box. With the other combination, the time lag was, as far as could be judged, entirely done away with, unless the push button switch were so lightly operated as to make carbon contact only, which of course reduces the current considerably. Increasing the power of the actuator box in this manner increases the amperes taken when the coils are reasonably cool, according to the following table :- | ||