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).
Switchbox modification for the Wraith and other models, adding a short-circuiting device for the ballast resistance.
| Identifier | ExFiles\Box 166\3\ img053 | |
| Date | 4th May 1938 | |
| Ex/ c. Rm.{William Robotham - Chief Engineer} --------- 6090 DA{Bernard Day - Chassis Design}:3/G.4.5.38. WRAITH AND OTHERS. SWITCHBOX. Herewith please find blueprints of D.CD.649. To provide a short circuiting device for the ballast resistance, to ensure full volts on coil at starting, the switchbox is modified as shewn on D.CD.649. The ignition switch now controls the starter relay circuit, and this current now reads on the ammeter. This arrangement can be introduced as soon as the test is complete. DA.{Bernard Day - Chassis Design} | ||