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).
Failure analysis of four returned ignition coils.
| Identifier | ExFiles\Box 49\5\ Scan029 | |
| Date | 21th August 1923 | |
| X.4273. EFC {E. Fowler Clarke - Electrical Engineer} /T21.8.23. X.4273 - IGNITION COIL PRIMARY FAILURES Details of four coils returned from EP. {G. Eric Platford - Chief Quality Engineer} as faulty. N.B. Coils Nos. 2960 and 3009 were two of the first batch of three. Coil Nos. 3016 and 3115 were two of the second batch of three returned to EP. {G. Eric Platford - Chief Quality Engineer} Coil No. 2960. We do not find anything wrong with this. [Handwritten: Broken down by EFC. {E. Fowler Clarke - Electrical Engineer} ] Still in our possession. Breakdown in secondary. 2v current - 1.96. Coil No. 3009. A large portion of the primary winding was found to be subject to an intermittent short circuit. [Handwritten: Broken down by E.F.C. Definitely shorted.] 2V current 2.60a Coil No. 3016. Nothing was found wrong with this coil by Mr. Brock's Dept., and EP. {G. Eric Platford - Chief Quality Engineer} has since stated that it is in order and suitable for service, but it is likely that there is an incipient fault and we hope to be able to make this manifest in our special test. [Handwritten: Found to be weak on the secondary when tested.] 2V Current - 1.92a Coil No. 3115. Reported un-satisfactory by EP. {G. Eric Platford - Chief Quality Engineer} Passed Mr. Brock's test satisfactorily the second time and again reported unsatisfactory by EP. {G. Eric Platford - Chief Quality Engineer} This must also contain an incipient fault which requires clearing. [Handwritten: Broken down on secondary by C.M.P. ok at first.] 2V current - 2.02a EFC. {E. Fowler Clarke - Electrical Engineer} | ||