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).
Concerns over volt drop from a proposed wiring method for the 'Japan 3' and comparing it to the 20/25 HP scheme.
| Identifier | ExFiles\Box 59\1\ Scan021 | |
| Date | 8th March 1932 | |
| SECRET. X6040. To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Wst. To Ry. c. RV/RD. Hs{Lord Ernest Hives - Chair}/Wst.1/AM18.3.32. JAPAN 3. WIRING. We do not favour the method of tapping the main positive supply to the switchbox from the starter motor cable at the starter relay switch as shown on wiring diagram D.53401. We consider the volt drop in the length of starter cable will lower appreciably the voltage available for ignition when starting up. With a leaky H.T. system or a nearly discharged battery this would be serious as the effect is cumulative. We agreed tentatively to the 20/25 HP. scheme as we did not consider the volt drop with the smaller engine would be too bad and in any case there would be a stand-by magneto. Hs{Lord Ernest Hives - Chair}/Wst. | ||