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).
Page describing the electrical phenomena of current oscillation in primary and secondary circuits.
| Identifier | ExFiles\Box 4\5\ 05-page084 | |
| Date | 1st August 1920 guessed | |
| -15- Contd. current will overshoot the zero and become negative, and current oscillations will proceed for a while as already explained. The fall of current referred to takes place coincidently with a change of flux corresponding to this fall of current. Corresponding to this change of flux there is not only an E.M.F. in the primary winding and across the condenser terminals, rising perhaps to several hundred volts, but there also exists an E.M.F. in the secondary winding proportionally greater in the ratio of the numbers of turns, (see foot note p.12). An instant arrives very shortly after, but not absolutely coincidently in time with the instant of break, at which the secondary voltage has risen high enough to break down the secondary gap. The moment this occurs it may be considered that there is a complete secondary circuit inductively coupled with the primary, with a high value of coupling coefficient. It can be shown mathematically that the effect of this sudden introduction of the secondary circuit is to cause the primary current oscillation to be converted into an oscillation of very much greater frequency, greater amplitude, and much more damping than previously, so that the primary current, although consisting of a number of quick oscillations between the primary winding and the condenser, can be said to be reduced to zero almost instantaneously. Corresponding to this there is at the same time an oscillatory current in the secondary and across the high tension gap, of similar frequency and damping, but of amplitude reduced in the ratio of the numbers of turns, and of phase exactly opposite to that Contd. COPY TO BE SENT TO W.O.V. REED. H.R.S. | ||