Nikola Tesla Books
Books written by or about Nikola Tesla
To observe better the end of coil which was before connected to earth (or water pipe) was now connected to a wire run from one turn of secondary, that is from the turn which was nearest to earth connection of secondary. The connection was in the previous experiments
as illustrated in one, then it was changed to the connection shown in 2. Nothing was, in principle, changed by this connection, only a higher e.m.f. (initial) was obtained and the tuning was made easier. This I have found to be an excellent way to adopt in tuning coils. The results were as follows:
| I. | II. | III. | IV. | V. | Observ. |
|---|---|---|---|---|---|
| 168 | 3/4" | 3/4" | very small spark | small spark livelier | When the wire was taken off down to 19 turns there was no spark between the rods even at a distance of 1/64" but when the hand was approached to free end of coil, sparks would be drawn 3/4" long and then spark would jump between the rods. This obvious and easily explained. |
| 140 | 3/4" | 7/8" | 1/16" | â | |
| 112 | 5/8" | 1" | stronger | â | |
| 98 | 5/8" | 7/8" | â | â | |
| 84 | 5/8" | 1" | â | â | |
| 70 | 5/8" | 1" | â | â | |
| 56 | 3/4" | 3/4" | â | â | |
| 42 | 3/4" | 7/8" | much stronger | much stronger | |
| 28 | 3/4" | 7/8" | 5/16 lively | 5/16 still livelier | |
| 19 | 3/4" | 3/4" | almost nothing | small spark |
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