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).
Comparison of Remy 12-cylinder, Remy 6-cylinder, and Delco 6-cylinder 6-volt ignition systems.
| Identifier | ExFiles\Box 52\3\ Scan314 | |
| Date | 4th March 1920 guessed | |
| -1- NOTES ON THE COMPARISON OF REMY 12 CYLINDER & REMY 6 CYLINDER ALSO DELCO 6 CYLINDER 6 VOLT IGNITION SYSTEMS From the tabular comparison herewith it will be seen that Remy 12 is designed to operate satisfactorily with about twice as many primary breaks per second as Remy 6, and that Delco is somewhat similar to Remy 6. The primary resistance of Remy 12 is about 1/3 of that of Remy 6, and the inductance is about 2/5. The ballast resistance during normal running conditions (900 R.P.M. of breaker, i.e. 10800 breaks per minute for Remy 12 and 5400 breaks per minute for Remy 6) is 3/2 times as great as for Remy 6 with the consequence that although the "time constant" of Remy 12 is about 5/4 of that of Remy 6, when the ballast resistance is not taken into account it becomes only about half as great as when the ballast is included + the "time constant" being the time taken by the current to rise to .632 of its final value) (We are here legitimately assuming that the ballast resistance does not increase in magnitude during the rise of primary current, which is true for such rapid action). * It is also to be noted that the ratio ballast resistance / primary resistance is more than twice as great in Remy 12 as in Remy 6 and that the ballast has very much more to do. (See effect of varying ballast, under mathematical and experimental investigations of action of induction coil.). | ||