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).
The routing of the H.T. magneto wire for a 20 HP chassis to avoid induced sparks.
| Identifier | ExFiles\Box 52\1\ Scan110 | |
| Date | 1st June 1929 | |
| X4473 To: from EFC {E. Fowler Clarke - Electrical Engineer} /HEW. [To: is struck through] C.C. SG. {Arthur F. Sidgreaves - MD} [C.C. SG. {Arthur F. Sidgreaves - MD} is struck through] EFC {E. Fowler Clarke - Electrical Engineer} is absent EFC {E. Fowler Clarke - Electrical Engineer} /HEW3/AML1.6.29. 20 HP. Chassis - H.T. Magneto Wire. We have received your E3/M10.6.29, and note your remarks re mutual induction. This point certainly escaped our notice at the time of our suggestion. The 20 H.P. battery ignition wires are taken through a completely insulated bakelite tube, but no trouble has been reported due to static induction, probably because the spark energy of the battery ignition sparks is less than the magneto. There might, therefore, be a possibility of induced sparks occurring on the battery ignition wires when the R.O.1 magneto H.T. wire is taken through the tube, as was the case earlier on with the Phantom, where the magneto wires were sandwiched with the battery ignition wires in an insulated tube. Your alternative scheme taking the wire round the front end of the engine, would, therefore, appear to be the safest. EFC {E. Fowler Clarke - Electrical Engineer} /HEW. E.F.C | ||