Radiant Electriciy Generated with Spark Gaps and Induction Coils - Theory

[nix85]

Another good video about this

https://www.youtube.com/watch?v=7Sgtq-ncZAE

I knew this but i didn't apply it to Tesla coil secondary. I already talked on this forum how impedance of an antenna is repeated every half wavelength down from the antenna, it does not matter what the characteristic impedance of the transmission line is (have to take into account velocity factor of the feedline).

Z = sqrt( L / C ) transmission line characteristic impedance

Along the open ended transmission line voltage and current waves reflect back and produce voltage and current nodes and antinodes 90° offset. Overall current being zero.

When we bend the end of the TL outward like an open capacitor we have an antenna and now energy can radiate.

We don't want standing waves along the transmission line which happens due to impedance mismatching of the antenna and the TL, only in the antenna itself. But there is no perfect matching so we have standing wave ratio etc.

Great demonstration of impedance matching vs standing/traveling waves.

https://youtu.be/DovunOxlY1k?t=795

[onepower]

Nix85

You are incorrect about the current being uniform in the secondary of a tesla coil with one open terminal.

First, the top or open terminal of the coil is the point of highest potential because the other end is usually attached to ground. Since it is at the highest potential it alternates between max/min charge density. Ergo the current cannot be the same at the top because the charge density is not the same due to the Coulomb forces present.

Thus as the potential changes so does the charge density and so must the motion of charges or current.

Your confusing a low voltage closed system with a high voltage open one which follows different rules.

Regards
AC

[nix85]

Seems you are incapable of understanding English. My post above literally says "Gotta correct myself" followed by a diagram showing IV distribution in the secondary and highlighted "current in the base is high and diminishes along the height of the coil". Which i further elaborated in next post about standing waves, IV nodes and antinodes in TLs and antennas and waves in any medium. I am not confusing anything, you are. This IV distribution applies to low voltages as well. Video of Jeri Ellsworth i linked clearly shows voltage and current distribution in a loop antenna with low voltage signal. Read, onepower, read.

Speaking of Coulomb forces you should've mentioned that Coulomb forces, that is, repulsion between electrons is the reason it takes higher voltage to pack more electrons on the plate of a capacitor, obviously, higher the electron density higher the repulsion to further electron inflow to the plate.

But electrons don't always repel, in superconductors they form Cooper pairs and their masses are less than masses of two electrons making them. Electrons also join in spark gap discharges in phenomena termed Electrum Validum aka 'strong electron' etc.

[nix85]

This is the best animation of halfwave dipole radiation, the memory effect aka kink etc.

https://www.youtube.com/watch?v=ZaXm6wau-jc

[nix85]

This video is bar far the best

https://www.youtube.com/watch?v=7Sgtq-ncZAE

I might also add a little about Helical antennas which i studied in depth years ago. Basically, if circumference of a coil is equal to a wavelength it will radiate circularly polarized waves in axial mode, that is, straight forward, they are used in space communication (because they are not angle-dependent and don't need perfect alignment), and if circumference is not equal to wavelength it will radiate sideways like a monopole. Circularly polarized waves can also be produced by two orthogonal halfwave dipoles 90° outta phase.