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).
Faulty 3TG3 ignition coil from chassis 5-GII, identifying a break in the secondary winding.
| Identifier | ExFiles\Box 47\4\ Scan071 | |
| Date | 15th September 1924 | |
| X. 4118. To EY. from EFC. EFC3/T15.9.24. X.4079. RE FAULTY 3TG3 IGNITION COIL EX CHASSUS 5-GII (ORIGINAL EXPL CHASSIS). We have carefully tested this coil with a view to ascertaining the cause of breakdown, and below I quote from my assistant's report WA.{Mr Wallis}80, from which it will be seen that this is not the original type of failure of this type of coil as surmised, but is due to an ordinary break in the secondary winding. Perhaps you will kindly confirm that it is your desire that we should unwind this coil with a view to locating the actual fault. "The fault in this coil is considered to be "a break in the secondary winding; for the following "reasons:- " (a) The continuity of the windings could not "be demonstrated with a 4 V lamp( see prod.test spefn.) " (b) No reading could be obtained on a milliammeter "in series with the secondary winding and A.C. supply. " (c) The H.T. supply from the coil when running at "12 V on the rig would only spark across 3.5 mm. gaps. "The primary winding appears O.K. the current taken "by this winding being 1.15 amperes." EFC. | ||