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).
Investigation into coil failures, specifically the effects of temperature, casing materials, and condenser action causing electric shocks.
| Identifier | WestWitteringFiles\J\November1922\ Scan61 | |
| Date | 9th November 1922 | |
| EPC1/T9.11.22. -3- Contd. The various coils that have been tried on chassis differ slightly from one to another, but in all so long as they are in their Klo cases, the effect is produceable by running the engine so as to get the bonnet temp. high enough. The effect is accelerated by the presence of a conductor such as the hand or tin foil already mentioned on the outside of the coil case, in fact the effects are exactly as described in our previous report and the development from that time is merely that we have definitely located the source of the weakness in the bakelite (Klo) cases. Our remarks as regards the power of the coil still apply if the loss of the Klo cases is considered to be one of the losses of the system. On the other hand, if the coil is taken out of its case and allowed to operate the engine, or if a coil made up in a stabalite case is used, the phenomenon requires such extreme conditions to reproduce it that it can be considered not to exist. A definite shock is felt on touching the outside of the coil when misfiring is caused to occur by this means; in fact the distribution of potential is varied thereby to such an extent that anyone else touching a part of the metalwork of the chassis at the same time can also feel the effect. If we connect a tin foil on the inside surface of the coil case to the high tension, this does not alter the effect. The effect as previously explained seems to be a condenser action, not a pure one, but one with a big --- Contd. | ||