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 memorandum discussing current oscillation and the importance of perfect metallic contact in ignition circuits.
| Identifier | ExFiles\Box 45\3\ Scan003 | |
| Date | 16th April 1920 | |
| Contd. -3- EPC1/T16.4.20. previous to the instant of break. Experimentally we find that such a current oscillation needs very perfect metallic contact and that a contact which may be all right for an ordinary lighting current may not offer a suitable path for such an oscillation. It would appear that at a press contact which is not absolutely metallically clean, such a current has a sort of disruptive effect, owing perhaps to the relatively enormous amount of heat being generated there in an exceedingly small space of time, resulting in the condition that sparking of a splashing nature takes place at such a contact. In view of the above, we feel that it is very necessary to provide a suitable circuit as free as possible from imperfect connections, for such an oscillatory current. Referring to diagram herewith, it will be seen that the oscillatory current does not have to pass through the bow spring on our ignition but has to pass throughall the other portions of the circuit shown, including particularly the contact between the condenser housing and the contact breaker casing, and again, that between the contact breaker casing and the frame. This latter, owing to the oil film which may exist, would be the worse offender. Contd. ONE 'B' (151-2-1918 2.S) 1,001 Y SEPT 21 '18 | ||