Nikola Tesla Books
Books written by or about Nikola Tesla
| Capacity in primary circuit Total | Self-ind. in primary Turns of Reg. coil + conn. | Observation: |
|---|---|---|
| $! {{(8 \times 36) - 2} \over 2} $! bottles = 0.26 mfd approx. | 15 1/4 + conn. | Ball of 38.1 cm daim. |
| $! {{(8 \times 36) - 2} \over 2} $! " = " | 19 1/4 + " | Structure to be described later of iron pipes with ball of 38.1 cm. diam. at an elevation of 141 feet from ground approx. |
For extra coil:
| Capacity in primary circuit Total | Self-ind. in primary Turns of Reg. coil + conn. | Observation: |
|---|---|---|
| $! {{(8 \times 36) - 2} \over 2} $! bottles = 0.26 mfd approx. | 19 1/4 + conn. | with above structure connected to free terminal. |
For coil 404 turns used in preceding investigations:
| Capacity in primary circuit Total | Self-ind. in primary Turns of Reg. coil + conn. | Observation: |
|---|---|---|
| $! {{(6 \times 36) - 2} \over 2} $! bottles = 0.11342 mfd. | 8 + conn. | Tuning very sharp, no capacity on end. |
Remark: With excitation from secondary (first turn) obtained in a previous test of this coil:
| Capacity in primary circuit Total | Self-ind. in primary Turns of Reg. coil + conn. | Observation: |
|---|---|---|
| $! {{(5 \times 36) - 2} \over 2} $! bottles = 0.094255 mfd. | 17 1/2 + 2 primary turns + connect. | Tuning was not quite sharp. |
Colorado Springs
Oct. 15, 1899
Continuing the considerations made Oct. 9 on the influence of elevation upon the capacity and taking, instead of the calculated value of the self-induction of the coil used in the experiments, the value ascertained by experiment which, with corrections for one turn secondary and connecting wires, may be put at 0.04 henry, we have, assuming now the coil to have a capacity entirely negligible:
$! {T_{s} = {{2 \pi \over 1000} \sqrt{0.04 \times {38.1 \over {9 \times 10^{5}}}}}} $!,
224
October 14
He continues with coil testing with parameters he measured during two previous days as well. He performs measurements at high frequencies and he intentionally loosely couples the measurements circuits with the exciting circuit (oscillator primary). The goal is to find the circuit resonant frequencies with the three mentioned coils at various capacitive loadings.
October 15
Because of the arithmetical error made on October 9th (see commentary), he mistakenly concludes that the capacities of the ball are now somewhat less than before. Had he used the correct values, his conclusion would have been just the opposite.
October 15
He continues the measurements from Oct. 9 with corrections in parameters according to the results obtained on Oct. 12. Due to a calculation error made on Oct. 9, he draws the wrong conclusion that the newly obtained sphere capacitances are somewhat smaller than the previous one. With accurate values the conclusion would be exactly opposite.
