Nikola Tesla Books
Books written by or about Nikola Tesla
| In first case inductance of primary was 51,000 cm | } | |||
| " second " | " | 52,900 | " | |
| " third " | " | 67,400 | " | |
* All these readings and maybe previous ones to be revised.
Taking the inductance of secondary from measurements before made 9,557,000 cm. we have for Cs1, that is, capacity of secondary alone:
| Tp1 = $! {{2 \pi \over 10^{3}} \sqrt{{51,000 \over 10^{9}} \times 0.1296}} $! Ts1 = $! {{2 \pi \over 10^{3}} \sqrt{{9,557,000 \over 10^{9}} \times {C_{s}}_{1}}} $! |
} | Cs1 = $! {{0.1296 \times 51,000} \over 9,557,000} $! = $! {{0.1296 \times 51} \over 9557} $! mfd. Cs1 = $! {{9 \times 10^{5} \times 0.1296 \times 51} \over 9557} $! = 622.23 cm. |
Now calling Cs2 and Cs3 respectively, the capacities of the secondary system with the connecting wire and with wire and structure respectively, since the capacity in the primary was in all cases the same, we have:
Cs1 : Cs2 = 51,000 : 52,900 and Cs1 : Cs2 = 51,000 : 67,400
and
Cs2 = $! {52,900 \over 51,000} $! x 622.23 = $! {529 \over 510} $! x 622.23 = 645,41 cm.
This gives capacity of connecting wire alone:
Cs2 - Cs1 = 645.41 - 622.23 = 23.18 cm.
Similarly we have:
Cs3 = $! {67,400 \over 51,000} $! Cs1 = $! {674 \over 510} $! x 622.23 = 822.32 cm,
and from this the capacity of the structure (the effective capacity) would be:
Cs3 - Cs2 = 822.32 - 645.41 = 176.91 cm.
But since
Cs3 : Cs2 = 67,400 : 52,900 = 674 : 529
we have Cs3 =
Cs3 = $! {674 \over 529} $! Cs2 = $! {674 \over 529} $! x 645.41 = 818.54 cm.
This value checks those formerly found and shows that the readings were fairly close. The test shows however that this method of determining capacity will only give a correct value when the distributed capacity is quite negligible. This observation has already been made.
286
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.
