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).
Experiments on ignition coil secondary winding arrangements and justifying the standard design.
| Identifier | WestWitteringFiles\N\2October1925-December1925\ Scan184 | |
| Date | 26th November 1925 | |
| ORIGINAL. To R.{Sir Henry Royce} from EFC. c. CJ. H.{Arthur M. Hanbury - Head Complaints} c. EY. RG.{Mr Rowledge} EPCA/T26.11.25. RE IGNITION COIL. X4100 Owing to certain recent correspondence in the technical press in which the originator contended that it was wrong for the inside end of the secondary of an ignition coil to begin from anywhere but earth, i.e. to be connected to the primary winding in any way, a coil with such an insulated and independently earthed secondary has been experimented with upon the bench. Thus various experiments have been made, but in none of these has there been the slightest indication of any advantage or any different effect in any direction, a result that was surmised before the experiments were commenced. So in view of the fact that constructional problems are much easier when the inside end of the secondary is connected to the primary, there would seem no reason to depart from this and every reason to keep to our standard arrangement. The arrangement of insulated secondary has been used a good deal by some of the American ignition firms, though one writer, himself a member of one of these firms, contended that there was nothing to be gained by it. EFC. | ||