Nikola Tesla Books
Books written by or about Nikola Tesla
These readings were:
| e.m.f. | { | 214 | } | I | { | 10.7 | } | Ï = 880 |
| 212 | 10.6 | |||||||
| 210 | 10.5 | |||||||
| from this $! {\left({E \over I}\right)} $! = 20, $! {\left({E \over I}\right)^{2}} $! = 400 | ||||||||
Average values:
|
||||||
| R = 7.9 ohm. R2 = 62.41 |
$! {\left({E \over I}\right)^{2} - R^{2}} $! = 337.59 $! {\sqrt{\left({E \over I}\right)^{2} - R^{2}}} $! = 18.375
L = $! {{18.375 \times 10^{9}} \over 880} $! cm
= 20,880,682 cm, approx. = 20,881,000 cm.
The inductance of the coil as ordinarily used would then be approx.
= 83,524,000 cm.
Colorado Springs
Nov. 15, 1899
Experiments with secondary of oscillator to determine capacity of structure, also capacity of secondary.
The readings were as follows:
| Secondary alone. | |
| Capacity in primary | Inductance in primary |
| $! {{8 \times 36} \over 2} $! = 144 bottles = 0.1296 mfd | 14 3/4 turns + connections. |
| Secondary with connecting wire leading to structure. | |
| $! {{8 \times 36} \over 2} $! = 144 bottles = 0.1296 mfd | 15 1/4 " + conn. |
| Secondary with structure connected to free terminal. | |
| $! {{8 \times 36} \over 2} $! = 144 bottles = 0.1296 mfd | 19 " + conn. |
* These readings approximate.
285
November 14
He measures the coil with 1314 turns but so that two coil halves are connected together in parallel. He expects that the connection of two halves in parallel should provide one quarter of entire coil inductance, which is approximately obtained in this case because the ratio 1/d of the tested coil is fairly large (please see Nov. 10). He performed the measurement at the frequency of 140 Hz, similar to Nov. 10) when he measured the entire coil inductance. The measured value is four times larger now and amounts to 83,524,000 cm and the previous measurement of the entire coil provided 85,000,000 cm. The small difference proves Tesla's claim that the inductance is almost four times larger.
November 15
Tesla again measures the capacity of the sphere on top of the metal pole as on November 7th and 12th, but with the secondary coil of the oscillator instead of the earlier âsupplementaryâ coils. The results did not agree with those obtained earlier. Tesla puts this down to the large distributed capacity of this coil, but it would seem that other factors influenced the accuracy as well. Because of the tight coupling between the primary and secondary of the oscillator, it was probably producing a compound spectrum.
November 15
He repeats the measurement of the sphere capacitance placed on the structure made of metal pipes as on Nov. 7 and 12, but with the secondary oscillator coil instead of the previous ''auxiliary coils''. This time he does not achieve the matched results with the previous ones. Tesla considers that the reason for that is that distributed capacitance of this coil is large. It seems, however, that other effects as well influence the accuracy of the results. Due to a very good coupling between the oscillator primary and secondary the oscillator spectrum is probably complicated and that, e.g., could significantly influence the measurement results.
