HF HV Phenomena Observations

[Farmhand]

Hello all, I've been having some fun with HV HF coils and got some pics and video's so I thought I would start a thread for interesting and fun things we see and do, any cool effects, sparks, arcs, plasma even strange vibratory or sound effects are welcome to be posted here.

Basically a thread for fun and interesting stuff. We all need a bit of fun and a good laugh every now and then.

So I'll start with some pics and a video of a small Tesla type coil, I'm using an igition coil and a spark gap for this, the ignition coil is powered from the secondary of a transformer/converter. The primary capacitance at the moment is only 0.6nF rated to 48Kv, I haven't tuned it yet to get the capacitance correct or the primary and secondary resonant together. So I hope I can get it better yet. I also have no RF ground stake so the arc is just floating between the bottom of the coil and the top.

Video link
‪Small Tesla Coil‬‏ - YouTube



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Feel free to post picture's and video's of fun stuff here.
No need for any in depth theories on anything. Just Picture's and video's and a bit of a description to go with them along with any comments or observations anyone thinks is relevent, that kind of thing.

I noticed that this setup seems to spray the arc from the bottom of the coil which is connected to the rivet hanging down, I was thinking that might be because I have no ground connection yet. I've got an 8 foot ground rod coming today so I hope that enhances the effects.

[Neight]

something funny I have noticed in two of your videos...
when you have some sparks flowing, you also have a rooster that gets excited
was just checking out some of your recent vids and happened to notice the crowing in the background.
cool stuff, and great still shots of the arc!
good idea to start this thread, you never know what will come out of this kind of talk

[Farmhand]

Hi all, As I was messing around trying to make different arc patterns I noticed I was getting some "musical" note's from the setup in the video.

I could swear it is stepping through a series of notes at some points. I'm just changing between two frequencies and also two power levels into the ignition coil.

Tesla coil musical note's video.
‪Tesla Music.wmv‬‏ - YouTube

I have no idea about music to comment. Except to say I'll try to work out how I can play the tune to close encounter of the third kind.

Here's a couple of pics too.


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Cheers

P.S. I've got a few roosters Neight, they don't like strange noises but they like to make noise themselves.

[Joit]

Can you play "happy Birthday" with the Coil? Then it would be a nice present.

But i got the same Observations with HV once.
The Frequency did not change seamless, but in certain Jumps.
I assume, that it has do do with the Capacity from one of the Coils.

[Farmhand]

Can you play "happy Birthday" with the Coil? Then it would be a nice present.

But i got the same Observations with HV once.
The Frequency did not change seamless, but in certain Jumps.
I assume, that it has do do with the Capacity from one of the Coils.

Haha, No no happy birthday tune's yet. I'll have to have a good think and do a bit of experimenting with different ways of using the arc, like bigger washers and different discharge points and whatnot.

I've seen coils that play music in the arc but they have the music input somehow. I don't want to use an instrument or midi player or anything to put music into it, I just want to be able to hit a few note's with the coil itself producing the note's. So I can use it to play tune's of its own sounds. Which might be more trouble than it's worth.

Here's a pic of the soundtrack from the video clip in audacity. Since I know nothing of music it is just a pretty picture to me. Seems to be quite a bit of sound energy there. Can we measure O.U. by sound energy emmited ? Because Tesla coils are very loud when they are spark gapped.


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Cheers

[Farmhand]

Hi all, here's some plasma in a light bulb.

Plasma Globe-1.wmv - YouTube

Couldn't get a decent photo.

[Farmhand]

Hi all, just in case anyone was thinking of building a Tesla coil for experimenting,
I am putting some resources here to help. I'll add some links, drawings and stuff
in here.

These two PDF's were quite helpful.

Table Top Tesla Coil
http://lloydritchey.com/downloads/Ta...sla%20Coil.pdf

Son of Tesla Coil PDF.
George Trinkaus - Son of Tesla Coil.pdf

This is the primary circuit I use but without the Magnetic quenching.


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And some web tools

Tesla coil calculator
OLTC Calculator

LC resonance calculator
L/C Resonance Calculator

This site below has helped me a great deal to understand the tuning and
operation of the coils. The link is to the tuning section but there are other
sections.
Oscilloscope Tuning a Tesla Coil for Resonance

And another very good web resource.
DC Tesla Coil design

Now for the bad news, being that a resonant condition is required, some
tuning is needed. As I am in the process of building some new coils I will
record and post specific details of the coils I build. As I build the new coils I
will use a function generator to determine the secondary resonant frequency
with a given toroid terminal size and the primary frequency range, caps needed
and so forth.

The small coil I've been using is a bit unique and not a "usual" design, and I
was lucky enough that it just kinda works the way I built it. It is a small solar
garden light lens and stand turned upside down with the light part removed,
this gave me a cone shaped coupling coil form with a helical resonator coil
form on top, the conical section is wound with some 0,5 mm wire and the
helical section with 0.2 mm wire, the primary is an inverted conical and has 1
tap on the second turn wound with 1 mm wire, the primary capacitance I'm
using now is about 1 nF.

Here's a picture I drew when I conceived the garden light coil former. I guess
it kind of resembles an electric candlestick.


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And here is a picture just after winding it. I used up some leftover bits of 0.5 mm
wire, the joins were soldered very carefully so that no sharp points were
created and the joint was smooth and curved. I made the primary a fraction
too close at the bottom and a ring of streamers forms between the bottom
primary turn and the secondary if I use a fair bit of power I'll try to get a
pic of that.



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The new coils I'll build will look much like these, I'll actually be using the coils on
the long former in this picture to make them, I just need to wind the primary
and coupling coils to go with them. The primaries will be different. I think the coils
will be resonant at around the 1 Mhz mark and should produce 40 Kv at the
top terminal and be able to maintain 40 mm arcs with about 5 or 6 watts input
power.



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I'll post more as I gather the info.

Cheers

[Farmhand]

Hello everybody, I made an improvement to the way I am producing disruptive
discharges to study. I'm now using a mosfet switch to pulse the ignition coil
primary with variable voltage from a large capacitor bank. I'm also using a dual
series spark gap which seems to work very well. I have tuned the transformer
to work at 45 Khz resonant to charge the capacitors as quick as possible with
as little input as I can get. I kept input power to 10 watts or below for this
experiment, it can take a lot more.

Doing it this way the spark gap can be made wide and if the spark stops the
voltage of the caps that the ignition coil is pulsed form increases and so ensuring
the spark gap refire's. And also one gap seems to spark green and one blue. cool.

Basically with 3 mm's of spark gap I can get 50 mm sparks and good forking
discharges with some small brush discharge from the grounded approaching object
(fluro tube) before arcing.

Here's the video -- You Tube Disruptive Discharge 2-1 Experiment --

The sound of the coil arcing like that reminds me of the Hemi motor in my old chrysler. It was tuned too.

Now my plan to improve the pre - disruptive discharge coil arrangement is to
design and build an air cored ignition coil style resonant high voltage coil to
replace the regular ignition coil, I hope to be able to pulse it at 200 Khz plus
with 100 v plus input to charge the primary cap for the main coil, this way
with an air cored coil The spark gap can fire on every cycle peak of the
charging HV coil. I plan to employ a voltage doubler to the supply transformer
to increase the output voltage to over 100 volts.

Here is a sketch of the arrangement I used, the supply transformer is simplified
for ease of drawing.



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And a picture.



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I will attempt to get some good arc photos later and post them

The New Tesla coils I'm building will be fully spec'ed, so if anyone wants to
they should be able to build one from the drawing and have it resonant in no
time at all, using easily obtained and uniform sized materials.

Cheers

[Itsu]

Dancing HV wire

Hi Farmhand, nice thread, intresting too, i did not see it before.

Just found an interesting effect when playing with a FlyBack transformer, which
kind of fits this "HF HV Phenomena Observations" thread.

I guess its static electricity on the thin isulation of the copper wire which is attracted to the blocknote paper.

Video to be seen here: dancing Flyback wire - YouTube

Have fun, keep it safe, regards Itsu

[Raui]

Hello Itsu,
Great demonstration! I believe your judgement of the situation is correct and that it is an electrostatic attraction effect between the insulating wire and the paper which is no different to the magnetic attraction between an electromagnet and magnetic material, say iron filings. The reason it appears only at high voltage is because the strength of an electrostatic field resulting from one volt is no where near the strength of the magnetic field resulting from one amp and hence our skewed view of electrostatic vs magnetic phenomena.

Raui

[Farmhand]

Hi Guy's, Itsu that wire is moving a lot, very interesting, that could be useful.
So many things to observe and think of ways to use.

I blew a mosfet, the ignition coil switch, i replaced it and installed a fast
recovery protection diode from source to drain and also a fast recovery diode
from the ignition coil negative to another charge battery which returns to the
ignition coil supply. I have three batteries charging now from two charge points
and both times i connected a charge battery to cool things down the spark gap
ran faster and it used less power. I also grounded the ignition coil negative
and still the grounded terminal charges a battery through a diode.

Almost all the input is either being recycled through the system, absorbed by
the charge batteries or spat out the Terminal of the Tesla Coil. I'll have to
find something else to waste some power with.

I've copped a couple of good zaps before I grounded every thing properly.

Thanks for the input.

Cheers

[Farmhand]

Hi salejerseys, you're very welcome, it is very interesting stuff to watch, it's just
a shame the sparks don't look the same on video as in real life. I'm happy to say
I'm almost finished my new small pair of coils, they will be resonant at about 640 Khz
which is less than I first thought but good. I'll be shooting for a 4 turn primary
with 10 nF of primary capacitance the online calculator I use tells me it should
produce 72 Kv and 10 inch sparks with 3000 volts input to the primary, which
sounds like fun. I doubt the 10 inch sparks though. I'll have two the same

I've calculated my terminals to be about 10 pF. I'm taking details and I'll post
a full specification list, compared to my other bigger coils these are tiny but
only slightly higher frequency and compared to the little one above they are
much easier to build and have a lot less wire and resistance. They have only
10 ohms resistance in the secondaries for 4.2 mH inductance so I'm guessing
the power in and out of these coils will be more than the others.

The benefit of using the two part secondary system is a few fold, another
benefit is that the sum of the inductance's of both coils is less than it actually
is when they are connected, because the top of the "A" coil is slightly above
the bottom of the "B" coil, this increases the inductance of the coils, in Tesla's
Magnifier patent he says this also reduces the chance of streamers from one
coil to the other, it does however give another way of tuning the coils, by slightly
raising or lowering the "B" coil into the "A" coil the resonant frequency will be
altered and the secondary coils can be matched this way to begin with. Which
will make the other tuning less and easier.

Hopefully I'll get a first test run in tonight.

Cheers

[Farmhand]

Hi guys, I finished the coils and tuned them with the function generator, The
primary capacitance is 16 nF, the coils produce an interesting wave form, with
three waves at different amplitudes or levels, the coils also produce a strong
wave form at lower frequencies, particularly 180 Khz. They are resonant at
about 560 Khz now which is lower again than I thought.

Anyway here's the coils.


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Here's the waveform at 560 Khz.


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And this one is at 180 Khz I think.


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If I use two coils together I wonder if I'll get 6 waves for the price of one.
Three waves from one coil, so six waves from two coils, or will it be nine.
Hopefully they make pretty sparks.

Cheers

[Farmhand]

I seem to have some insulation issues so if i use too much power I get stray
arcs crawling all over the bottom of the coils, I managed to get most of it under
control but I might need to make some adjustments.

Here's the first test video.
Small Tesla Transformer Test.wmv - YouTube

Cheers

[Farmhand]

OK this is getting better, here is a video of some low frequency lightning type
discharges, the purple "leaders" form from the grounded object towards the
Tesla coil Terminal and the white "lightning" type discharge forms from the
Terminal towards the grounded object in response and very suddenly, also the
Terminal to ground discharge is more direct and more intense, I imagine
because the purple leaders have formed the best path for the Terminal
discharge to take to ground. When it's working and discharging at that
frequency it sounds a bit like a Gatling gun.

THe discharges are quite powerful and seem to explode the air sometimes,
and on close observation I can see a kind of fine particle mist exploding away
from the grounded object. It's very hard to capture on film, but i'll try later.

50 mm Lightning.wmv - YouTube

I seem to have solved the leaking from around the bottom of the coils, and
the Terminals seem to be holding the charge OK and not leaking too badly.

I don't recommend holding a fluro while the coil discharges through it when
this kind or potential is present. Streamers might come out of ones feet to
the ground.

I blew out a neon so I'm now wondering what might be fun to expose to some
strikes. Any idea's, I can setup the camera on the tripod and try to film some stuff.

Cheers