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).
Test specification outlining procedures for evaluating magneto sparking performance.
| Identifier | ExFiles\Box 4\5\ 05-page108 | |
| Date | 11th September 1927 guessed | |
| -3- Contd. and the slowest speeds at which regular sparking will occur for:- (a) Fully advanced position (b) Central position and (c) Fully retarded position, shall be ascertained. Note:- The minimum sparking speed can be taken to be that speed at which 100 consecutive sparks, without missing, are given by the magneto at some time within a period not greater than 5 minutes. (15) The high speed sparking characteristics of the magneto shall now be investigated. No general rule can be laid down, but remarks should be made as to what speed and under what circumstances the magneto fails to spark, and in particular, the effect of flux distortion shall be noted from the unequal character of the sparks on the two sides of the magneto, if such a difference obtains. (16) The speed at which the contact breaker lever begins to fling shall now be ascertained by the instantaneous vision method, making use of a second magneto driven as nearly as possible at half the speed and operating a high tension condenser spark discharge, but the light of which the contact breaker of the magneto under test shall be viewed. (17) The resistance of the primary winding cold of (state temperature) of the armature shall now be obtained by the volt and ampere method, due allowance being made for the necessary correction to be applied to one reading. Contd. | ||