Does a 1/4 wavelength Tesla Coil produce DC instead of AC?
Someone said coils with a physical length of 1/4 wavelength will produce pulsed DC instead of high frequency AC. In other words, they said that when a Tesla coil is at 1/4 wavelength, the HF AC it it produces will become rectified into DC. They gave a quote from a book entitled “The Electromangetic Interaction” by Robin L. Armstrong, 1973, to support what they said. Here’s the quote:
“Since electromagnetic effects are not transmitted instantly from point to point in space…there is a time lag between changes in charge and current distribution on the dipole’ which ‘…allows some of the energy to continue flowing outward even though conditions at the dipole may have changed to indicate an inward flow of
energy…as if some of the electric and magnetic field has become detached
from the dipole or “shaken off” by the oscillation.”
I would really like to know if this is true, and would greatly appreciate of a real Electrical Engineer can give me their opinion on this. Thank you
I think you misunderstood what is being stated. Tesla coils only work with and only produce AC current. Transformers which are at the heart of a Tesla coil can be a variety of shapes and lengths.
Even antennas which are designed to detect and receive AC or Radio waves may have a physical length that is 1/4 of a wave length. This is accomplished by properly establish a ground plane.
Why do you want to rectify AC power from a Tesla Coil into DC power?
Hi,
Thank you for your answer and source provided. The reason you would want to rectify it, according to the person I was talking to, was to have a high voltage direct current source. I understand how Tesla coils work and that they operate on AC, and are used to produce HF HV AC. This person said that in a quarter wave Tesla coil, the output on the secondary becomes DC instead of AC.
So what your saying is that this guy misinterpreted the quote from that book. That’s what I thought too. Could you please explain the correct interpretation of that quote I gave. Thank you again.
Peter.
There are a number of ellipses in the quote you provide. I am not familiar with the book. Do you have the complete quote?
You may want to read the reference supplied in my original quote it provides information on how an antenna works.
I am assuming in your original post you are really talking about transmitting AC using a Tesla antenna. Is that correct?
Also read the reference noted below on rectifiers.
a tesla coil tuned to 1/4 wave length or even 3/8 wave length will produce a DC brush.
below is a a link to a patent that explains the phenomena…