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).
Trials of 'amplokons' with a magneto, assessing their effect on sparking performance under various conditions.
| Identifier | WestWitteringFiles\I\July1922\ Scan25 | |
| Date | 4th July 1922 | |
| PB.42. COPY July 4th 1922. Trial of Amplokons with Magneto. These tests were made with the amplokons submitted, in connection with a U.S.A. Bosch Z.R.6 magneto. The effect of these was first tried on the slow speed spark of the machine. Two of the six gaps were fitted with the accessories, and adjusted to 5.5 mm. The timing lever of the magneto was retarded. It was found that regular sparking could be obtained at a lower speed without, rather than with the amplokons; the actual figures being:- Without .155 r.p.m. With 170 r.p.m. The same gaps were then tried with the magneto running at 1500 r.p.m. and timing lever central, and made wider with the object of finding the largest gap at which regular sparking would occur. The results were as follows :- No.1 gap. No.2 gap. Without 5.5 mm. 7.5 mm. With. 6.5 mm. 7.5 mm. Results almost identical with those obtained with the amplokons, were obtained by means of a small external gap of about .5 mm to 1.0 mm. It will be seen that the effect is a tendency to level up the gaps by assisting the one that appears to be weaker (due perhaps to some leakage) while the other remains unaltered. A decided leak was then provided for each of the gaps, in the form of the secondary winding of a coil connected across and the largest regular sparking gaps obtained for 1500 r.p.m. of the magneto with timing lever again central. They were as follows :- No 1. gap. No.2 gap. Without 4.5 mm. 4.5 mm. With 5.5 mm. 5.5 mm. In this case the amplokons certainly improved matters. It appears then that the amplokon is of no use until a leakage occurs across the main gap, and that practically the same results can be obtained by a small external gap. C.A.P. | ||