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Nikola Tesla Books

Books written by or about Nikola Tesla

Nikola Tesla: Colorado Springs Notes, 1899-1900 Page 249

October 30, 1899

To get better readings for the separate turns of the regulating coil the voltage was taken again as first across the whole: 2 primary turns, connections and regulating coil all in series and the turns of the latter were then varied, readings being taken for each case. The results are indicated below:

E I Number of turns of the regul. coil included in the circuit ω Resistance total of circuit included
11.55 55.8 0.5 867  
11.675 55.8 2.5 "  
11.90 55.8 4.5 "  
12.15 55.3 6.5 "  
12.45 55.3 8.5 "  
12.80 55.3 10.5 "  
13.20 54.9 12.5 "  
13.50 + a little 54.9 14.5 "  
13.90 54.9 16.5 "  
14.25 54.4 18.5 "  
14.60 + a little 54.4 20.5 "  
14.15 51. 22.5 "  
14.30 51.1 23.5 "  

To facilitate estimation of the inductance of the various turns the readings were reduced to the same value of current and are as follows:

E I Number of turns of the regul. coil included in the circuit ω Resistance total of circuit included
11.55 55.8 0.5 867  
11.675 55.8 2.5 "  
11.90 55.8 4.5 "  
12.26 55.8 6.5 "  
12.562 55.8 8.5 "  
12.915 55.8 10.5 "  
13.416 55.8 12.5 "  
13.721 55.8 14.5 "  
14.128 55.8 16.5 "  
14.617 55.8 18.5 "  
14.976 55.8 20.5 "  
15.452 55.8 22.5 "  
15.616 55.8 23.5 "  

249

Source:
by Professor Aleksandar Marinčić

October 30-31

He continues measurements, which involve the primary coil of the big high frequency transformer, regulating coil and the inductance of the connections. The wiring scheme is shown on Oct. 30; except that the short circuit is established via a rotating arcing device and a capacitor. So only the above mentioned inductances remain in the circuit. The measurement method has been explained several times so far. As a new item it is explained how the signal of the frequency of approximately 140 Hz is produced and how the frequency measurement is performed.

On Oct. 31 he determines the new coil parameters by measurement. This coil was made by rewinding the coil with 689 turns which was mentioned on Oct. 22. He takes thicker wire in order to improve the quality factor. Measured values he compared with calculated values.

Contents

Introduction
June 1 - 30
July 1 - 31
August 1 - 31
September 1 - 30
October 1 - 31
November 1 - 30
December 1 - 31
January 1 - 7
Commentaries

Appendices: I, II

Images

Glossary

Lowercase tau - an irrational constant defined as the ratio of the circumference of a circle to its radius, equal to the radian measure of a full turn; approximately 6.283185307 (equal to 2π, or twice the value of π).
A natural rubber material obtained from Palaquium trees, native to South-east Asia. Gutta-percha made possible practical submarine telegraph cables because it was both waterproof and resistant to seawater as well as being thermoplastic. Gutta-percha's use as an electrical insulator was first suggested by Michael Faraday.
The Habirshaw Electric Cable Company, founded in 1886 by William M. Habirshaw in New York City, New York.
The Brown & Sharpe (B & S) Gauge, also known as the American Wire Gauge (AWG), is the American standard for making/ordering metal sheet and wire sizes.
A traditional general-purpose dry cell battery. Invented by the French engineer Georges Leclanché in 1866.
Refers to Manitou Springs, a small town just six miles west of Colorado Springs, and during Tesla's time there, producer of world-renown bottled water from its natural springs.
A French mineral water bottler.
Lowercase delta letter - used to denote: A change in the value of a variable in calculus. A functional derivative in functional calculus. An auxiliary function in calculus, used to rigorously define the limit or continuity of a given function.
America's oldest existing independent manufacturer of wire and cable, founded in 1878.
Lowercase lambda letter which, in physics and engineering, normally represents wavelength.
The lowercase omega letter, which represents angular velocity in physics.