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 design and performance of the ballast resistance carrier for the 'Goshawk II' battery ignition system.
| Identifier | WestWitteringFiles\G\July1921\ Scan30 | |
| Date | 21th July 1921 | |
| To EFC. from R.{Sir Henry Royce} Copy to HS.{Lord Ernest Hives - Chair} ORIGINAL R1/G19/7/21. (4) X.3485. RE "GOSHAWK II" BATTERY IGNITION. X.3716. RECEIVED The ballast resistance carrier design sent through has an equal capacity to that on the Bosch ignition which is at present running on 4 EX. We do not know what ohms this is or what class of resistance wire, but as the ignition is running with tungsten points, we ought to be able to get comparatively the same working conditions with our arrangement. It should be remembered that the ballast resistance being low, ought to make the ignition more effective owing to the increase in the surging current, which seems to be checked by this resistance. We do not know whether it would do in a finer gauge or some other material. Originally this ballast resistance was made of a metal with a high temperature co-efficient. It would be as well to know what the Bosch Company have found good for this purpose, and what the Delco use on the American cars which we have. The temperature co-efficient would be a good guide as to the variety of metal which is used, and the resistance could easily be obtained. Most of these ignitions are perfectly effective at slow speeds, with the battery down to about half the volts. This seems necessary, because the ignition has to go on when the starter is taking its full current. R.{Sir Henry Royce} H H' 522V (200 L) (9'D' 408' 89-t-Ts') RW' S172eUP | ||