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).
Instructions for updating and adjusting an Auto-Switch E for 12 Ex.
| Identifier | ExFiles\Box 59\1\ Scan244 | |
| Date | 2nd February 1928 | |
| RR 238 (150 BKS.) (SH57.29-6-20.) MP 224358 X4008 ROLLS-ROYCE LTD. INSTRUCTIONS. To: EFC Order No: AC.99. Customer's No: X 4008 Date: 2. Feb 1928 Auto-Switch E for 12 Ex. This switch has now been brought up to date in the shop. The resistance winding consists of 12 ft of 30 swg Eureka in 49 turns and having 23.8 ohms resistance. Both the turns and the resistance are a little on the high side, but not seriously so. It is intended to use 21.0 ohms resistance in 40 to 42 turns. The switch has been adjusted in conjunction with a 30 hp dynamo, such that after heating on 17.0 volts, the points opened at 17.1 volts and closed again at 12.3 volts with the dynamo standing; falling to 12.0 volts with the dynamo running at 2500 rpm. Signed: (contd) This Sheet must be filed on completion of the work. | ||