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).
Synchronizing the advances of battery and magneto ignition systems.
| Identifier | ExFiles\Box 37\1\ scan 272 | |
| Date | 1st August 1924 | |
| Contd. -7- EFC9/127.8.24. The two advances of the battery ignition in this diagram are the same as at present on the 20 HP. Those for the magneto ignition are as specified in our general specification of magneto requirements. A linear relation between the degrees on the magneto and battery ignition on the one hand, and the ignition lever travel on the other, has been assumed, but it would appear more expedient so to arrange matters that the two ignitions synchronize more nearly in the more advanced positions of the lever, and further, to make the automatic advances as nearly as possible synchronize at every stage. This can probably be done with the servo, though it would be rather difficult to do it with independent governors, owing to one unit having three times the speed of the other. In regard to E's query about the amount of retard required on the hand control for a flick start on the battery ignition, will E.{Mr Elliott - Chief Engineer} please find attached copy of the development of a formula for ascertaining this, together with a copy of our covering note EFC2/T9.1.24, issued at the time. By means of the formula arrived at, substitution of the values of the four variables will immediately give the position of the hand control at which a flick start on the battery ignition should take place, this being equally applicable to the application of the R.R. battery ignition to the EAC2. It will be understood, however, that this pre-supposes a linear relation Contd. | ||