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).
Analysis of primary current consumption in relation to spark gap configurations and size in an ignition system.
| Identifier | ExFiles\Box 52\3\ Scan293 | |
| Date | 11th December 1917 | |
| H.R. 235 A (100 T) [S] 1M 846.8.19. (G. {Mr Griffiths - Chief Accountant / Mr Gnapp} 2460) Contd. -5- EFC {E. Fowler Clarke - Electrical Engineer} 2/T11.12.17. increased the primary current consumption slightly, i.e. about 5% , when using 6 separate gaps, and about four times as much when using one gap only. Thus in this latter case, the increase was from 1.65 amps. at no spark to 2.1 amps. at a very small gap, which was further increased to 2.5 amps. with the secondary shorted. Remy 6. Speed. 900 R.P.M. Primary gaps .028" Reduction of secondary spark gap length from maximum to indefinitely small, did not appreciably alter the primary current consumption, even when only one gap was used, but on shorting the secondary the primary current consumption was nearly doubled. The above effects must be put doen in the main to the greater ionisation of the shorter gaps, causing the secondary circuit to be partially shorted during the intervals between sparks. The effect on the primary is the usual effect of a second circuit linked with it, namely, that it causes the current to rise to take place more rapidly by lowering the effective inductance, thus increasing the average current. At the same time there will be a reverse induced secondary current. It is true that there are a larger number of sparks per sec, per gap from Remy 12 than from Remy 6, but this does not explain why the effect should be apparent with Remy 12 on 6 gaps and not with Remy 6 on one gap. | ||