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).
Technical analysis of the electrical characteristics and requirements of an ignition system's local circuit.
| Identifier | WestWitteringFiles\M\2April1925-June1925\ Scan62 | |
| Date | 7th May 1928 | |
| Contd. -2- RFC4/T7.5.28. good contact connections. After the contact points break has taken place, the current in the IC circuit is of the nature of a high frequency alternating current, the order of magnitude of the frequency being 10,000, the order of magnitude of ampere amplitude being 10, and the order of the voltage amplitude being 600. Such a current requires, to avoid resistances in its path, rather better than ordinarily good contact connections. Further, inductive elements of the circuits IP and IC, over and above the main inductance I are of little consequence as they merely add their effect to the main inductance. The most important circuit of an ignition system from both points of view of inductive and resistive effects, is the local circuit PC. The desired instantaneous (as nearly as possible) transference of the main current from the branch P to the branch C is equivalent to asking the local circuit PC to be capable of dealing with an alternating current of frequency many times higher than the previous frequency mentioned - a frequency in fact probably of the order of 100,000,000 and current amplitude of the order of 3 amperes. It is clear that for effective operation of this local circuit PC, there must be:- | ||