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).
Continued test report on a controller armature and cutout, detailing its action and electrical test results.
| Identifier | WestWitteringFiles\O\2April1926-June1926\ Scan240 | |
| Date | 21th May 1926 guessed | |
| AC.74. -2- Contd. The controller armature travels some distance before pulling the contacts apart and on reducing the magnetic pull, the return motion is in two definitestages (1) to the "on contact" position, (2) armature right back to stop. All the actions of cutout and controller are quite "snappy", due to the "overlap" or rapid increase of magnetic pull with travel, compared with return spring tension, but it causes thee cutout to take a large reverse current before dropping out. The shunt coils of the two elements of the unit are connected in series. A diagram shewing the internal connections and the external wiring for adapting to the R.R. system is attached. The polarity is shewn reversed to correspond with the Midgley labelling. Tests have been made on the apparatus as follows :- Cutout. (Battery off) In. Out. Shunt volts. 12.7 9.75 " amps. .185 .14 Series amps. (alone) 26.0 20.0 (Battery on). Shunt volts. 11.6 " amps. .168 Series amps. -4.5 ------------------------------------------------- 2.05 amperes in the series coil are thus equivalent to 1.0 volt on the shunt coil, in magnetizing effect. Contd. | ||