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30kV Jacob's Ladder that I made from an old TV

Razako

Razako

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A few months ago I saw one of those huge old TV sets out in the street for garbage pickup day. Being the electronics geek that I am I couldn't just leave it lying there for the other scavengers to find so I loaded it into the back of my truck and took it home. I got it home and tried plugging it in to see if it still worked. I heard the familiar high frequency hiss, but the screen stayed black. After a short analysis I determined that the picture tube in the back of the CRT was dead because there wasn't the normal orange glow coming from it in the dark. What could I possibly do with this old piece of junk?
[media]http://www.youtube.com/watch?v=k1aWfR4cQwI[/media]
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Btw you shouldn't throw those old CRT monitors away either.
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Razako

Razako

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And another video showing what this beast does to a piece of paper.
[media]http://www.youtube.com/watch?v=3pKbehoHg_Y[/media]
The flyback in the monitor is also cool, but it isn't nearly as impressive. It doesn't burn stuff and produces a loud crackly arc.
[media]http://www.youtube.com/watch?v=5OYlYvlwlCQ[/media]
 
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nikokapo

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Being the electronics geek that I am I couldn't just leave it lying there for the other scavengers to find so I loaded it into the back of my truck and took it home.
Click to expand...

i need to learn how to drive :(!!!!!!!!!


why do you people always find electronic stuff laying around there on the streets!?!? or getting stuff and transformers for free!!





btw the ladder is pretty amazing
 
Tw15t3r

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Wow! nice Job on the Jacob's ladder man! What did you use as the flyback driver? I remember I was playing with one using a very simple driving circuit of two resistors and a transistor.
Produced around 5kV I think.... max gap was only about a centimetre or so...
 
Switch

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Cool! :D I wonder, could that transformer be used to power an air laser? :-/
 
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carulli

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is the fly back an old disk shaped flyback, if so hook the main hv lead up to a light globe and have fun. if it has a ltitle stick on your flyback then that cold be a recifyer and it wont work for a plasma globe, mabye you could remove it.

ps DO NOT TOUCH THE LIGHT GLOBE IT WILL CUT THROUGH THE GLASS TO YOUR FINGER!!!!!

ill see if i can find pics of mine but by the look of it yours is outputting much more current then mine. how far away can the electrodes be away from each other for an arc to start.
 
Razako

Razako

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carulli said:
is the fly back an old disk shaped flyback, if so hook the main hv lead up to a light globe and have fun. if it has a ltitle stick on your flyback then that cold be a recifyer and it wont work for a plasma globe, mabye you could remove it.

ps DO NOT TOUCH THE LIGHT GLOBE IT WILL CUT THROUGH THE GLASS TO YOUR FINGER!!!!!

ill see if i can find pics of mine but by the look of it yours is outputting much more current then mine. how far away can the electrodes be away from each other for an arc to start.
Click to expand...
It's one of the older types and the main high voltage line goes from the disk to a little square epoxy filled box which might be some kind of rectifier. The box has 3 wires coming out. One is the main HV wire that I pulled out of the back of the CRT. It's putting out around 25-30kv of high frequency AC and I know this because I've successfully turned lights into plasma globes with it. The other two wires coming out carry HV dc and went to the pcb attached to the pins of the CRT. They only arc a centimeter at max so they probably only carry around 3-5kv.

If I use 2 needles as electrodes they start to arc at around an inch and a half with lots of corona discharge at 2-3 inches. If I leave it arcing for more than a few seconds it will actually melt the tips off the needles. I'll post some pictures this things guts later if you want.
 
Razako

Razako

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jamilm9 said:
how are you powering it
Click to expand...
It's powered by the original driver circuitry in the tv. All I did was pull all of the HV wires out of the dead CRT and put their power to other uses. I find it simpler than making a flyback driver from scratch.
Pictures:
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Picture020.jpg
 
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carulli

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just leve it the way it is as it will work better for a jacobs ladder but I will take pics of mine soon and show you how it looks yours wont work unless you cut f the box which by the way is a voltage doubler or trippler and sadly it will also rectify the output :'(
 
Razako

Razako

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Well it's now dead :'( Yesterday I turned it on and after a few seconds it died. I checked the fuses and they weren't blown so I'm guessing one of the transistors is fried or the flyback died. I really have no way of testing the flyback though so it might still be good. I took the thing apart and harvested all of the useful components. In all I got the flyback transformer, the voltage multiplier, some good resistors, and some high voltage capacitors.
 
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carulli

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it is a 99% chance that is was a transistor that blew up, unless of course there was smoke pouring out of the flyback itself ;D. you can ether make a new driver for it, or design your own. there are many schematics for them on the internet ;)
 
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