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).
Instrument illumination for the Wraith, detailing changes to lamp and dimmer resistance.
| Identifier | ExFiles\Box 168a\1\ img107 | |
| Date | 28th June 1938 | |
| 6135 c. Rm.{William Robotham - Chief Engineer} ---------- DA.{Bernard Day - Chassis Design}11/G.28.6.38. R.I. INSTRUMENT ILLUMINATION - WRAITH. In view of the report Rm{William Robotham - Chief Engineer}/RC.{R. Childs}7/10.6.38. it appears that the lamps vary in resistance so greatly to make it impracticable to run 3 in series. We have produced D.CD.756 shewing a design of lamp with resistance wire wound on outside to enable 2½ bulbs to be used on a 12 V.{VIENNA} circuit. D.CD.751 shews the deletion of the fixed resistance on the dimmer, and also the altered dimmer resistance value to handle the 2½ V.{VIENNA} bulbs. DA.{Bernard Day - Chassis Design} | ||