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Electro-globe experiments

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LAN_403

keantoken

Mon Nov 24 2008, 08:36AM

Registered Member #1442 Joined: Mon Apr 14 2008, 04:19AM
Location:
Posts: 13

Hello all. I am new to these forums.

I have been experimenting with HV things for a small while, with Tesla himself as my inspiration.

I thought I would post some pics as part of my introduction.

This small tesla globe is beautiful and powerful enough to draw about .75mm arcs straight off the glass with your finger. I am not terribly worried about burning it out, and if it does go up in flames I can get another. with a metal jar cap fastened on top with electrical tape (the cap actually doesn't touch the glass) I can draw a 5mm spark with a wire or needle (I use a sewing machine needle in the photo).

The wire drawing the spark is not attached to the actual ground. In the picture it is attached to the leg of my metal desk.

Things I have done:

1: burn holes in paper with the plasma streamer.

2: vaporize water.

3: vaporize salt water.

4: make salt cubes glow yellow. Sometime the salt cube would actually become transparent and melt into a ball! Coolio.

5: I have 2 xenon flash lamps which supplied amusement for all of 30 minutes. I also have 2 aquarium fluorescent bulbs that will light up if brought close to the bulb.

I did notice that the salt cubes would fly away sometimes when I brought the needle close to them. I did not hold the needle with my hand as any contact with the hot parts will result in painful burns. I used pliers with rubber handles. Still not much true protection, but the surface area is spread out across my hand so there should be no concentrated exposure points.

I am not very experienced yet so I would appreciate it if you would answer a few questions:

1: Tesla recommends linseed oil as an insulator. I read that it has a breakdown voltage of 300V per mil. Is this good for something you can get at your local paint shop?

Here is the link. You can download the whole book (from 1920's!) in PDF and I'll bet it has some useful information.

,M1

2: I had a cylindrical flash tube that looked very cool when I connected it up. It got pretty hot though (began to melt the rosin on a soldered joint!) and the glass began to discolor in some places that the streamers would avoid. I tried submerging it in linseed oil in a small jar I had. When I did this, it rapidly started making these chinking sounds but I could not see the glass cracking and did not see any evidence of gas leaks. I let it do this for about 10 minutes but it didn't die. Any ideas? I had another bulb that was not in oil that I was messing with, and it made the chinking sound once when the streamer inside jerked suddenly.

I may post some more pics later of the flash tubes.

- keantoken

1227515706 1442 FT0 Tesla Globe Hackin 007 Resized

Littlew

Mon Nov 24 2008, 08:04PM

Registered Member #1448 Joined: Sat Apr 19 2008, 01:16PM
Location: Russia/Moscow
Posts: 21

this is just Plasma Ball
inside this toy simple one-transistor(without heatsink(!) it gets REALLY hot) flyback driver that produce ~6000v AC

keantoken

Tue Nov 25 2008, 06:18AM

Registered Member #1442 Joined: Mon Apr 14 2008, 04:19AM
Location:
Posts: 13

This globe actually has a slider that allows you to increase the power. It actually doesn't get hot after a while of drawing a spark as in the picture. I thought that it had a 555 in there or something but I don't remember.

How much power would the flyback out of this be able to supply?

- keantoken

Conundrum

Tue Nov 25 2008, 08:17AM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

flash tubes have a conductive coating FWIW- that might be why its behaving strangely.

Interesting to note however that the discharge is mainly in the infrared- you might get some interesting results if you take a normal cheap webcam and replace its IR blocking filter with an IR transmissive/block visible one.

This is also fun to try with TC discharges, you can see all sorts of strange glow effects that you never see in visible light because they are too dim. (this is another use for my false colour imaging project!)

Tried this once with my Kirlian setup and the infrared from a barely visible glow discharge was unbelievably bright.

-A

keantoken

Wed Nov 26 2008, 07:38AM

Registered Member #1442 Joined: Mon Apr 14 2008, 04:19AM
Location:
Posts: 13

wrote ...
Tried this once with my Kirlian setup and the infrared from a barely visible glow discharge was unbelievably bright.

Hmmmmmm. Speaking of this, would I be able to take the flyback out of one of these plasma globes and make a kirlian photography device?

I should try and get a webcam soon so that I can begin my IR experiments...

- keantoken

Conundrum

Wed Nov 26 2008, 02:00PM

Registered Member #96 Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062

I would tend not to, better to use a CCFL (PC case mod light) as you will get zapped otherwise and also it will burn through and wreck your film (!)
You *might* be better off running it from a current limited supply such as 12V battery with an inline 22 ohm resistor, this will enable it to generate high voltages but limit the current to sensible levels.

Also the big problem is going to be regulating the glow discharge which will be dependent on surface area and plate distance. I found that running it from a variable power supply is the best bet but failing that just adjust it with a dummy used film in place and the object to be photographed, set up for correct corona with a safety inline switch and test it.

This is very dependent on plate distance, I also found that a thin sheet of acetate makes a passable dielectric, as does thin sellotape on the ground plate.

I used a 2 second exposure which is probably too long but was enough to get a nice image on the 8th attempt of a leaf.
Also did the same with a coin. WATCH OUT, if you overload your supply it will fry without protection system, this is why I have no pictures of my setup.

keantoken

Thu Nov 27 2008, 02:06PM

Registered Member #1442 Joined: Mon Apr 14 2008, 04:19AM
Location:
Posts: 13

I might be able to do a timed exposure with my webcam, not sure.

If I got some kind of fluorescent material or some fluorescent rubber tube things I could put this around the electrodes to provide some light for exposures.

- keantokn

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