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).
Technical specifications for the correct operation of main and secondary electrical circuits, detailing current, voltage, and resistance requirements.
| Identifier | ExFiles\Box 64\3\ scan0036 | |
| Date | 5th March 1925 guessed | |
| -3- Contd. The conditions as regards correct operation of this second circuit are therefore :- (a) The main switch must be definitely operated from the "off" position by a current of 2.4 amperes. (b) The current must be capable of being broken reasonably sparklessly. (c) When the main switch is operated, the main motor current is switched on and it must be considered that the available voltage must drop to 9. The available amperes through the coil will then be 2.37 amperes. It is necessary therefore that the main switch be capable of definitely holding on with a pressure of 30 ozs. on the contacts with a current of 2.0 amperes through its coils. Circuit 3. MAIN. The resistance of this circuit are as follows :- The heavy current coil on relay switch .001 ohm. Motor main field .015 " Motor armature .030 " Total .046 " 9 VOLTS Upon this main circuit being switched on, it is considered that the available voltage has dropped to 9. The initial ampere rush will therefore be 195.5 and the conditions for correct operation will be :- (a) The relay switch must be definitely pulled over by a current through its heavy current winding of 150 amperes. (b) The main contacts of the main switch must carry a current of 220 amperes for one minute without shewing signs of distress. Contd. | ||