This is a very simple and fun use of a dying computer monitor. Jacob's ladders have been around forever, but I don't think one has ever been made in this way before. However, it's dangerous as hell, so don't do it!
Afrotech's Computer Monitor
(AKA Afroman's ladder?)
For those who don't know what a Jacobs ladder is, its basically a nice visual display of a hot arc travelling upwards between two wires. Here here and here are some good links for information and pictures about quality ladders. Since I don't know the meaning of the word quality, I found a cheapass way to make one, and finally put my dying old Amiga monitor to use.
Here's my groovy 1988 1084 monitor. Open
any monitor up, and one of the first things you will see is a big suction
cup attached to the CRT. Attached to it is a wire that is at a few thousand
volts higher than ground because there is a capacitor somewhere that is
still charged up. The first thing you should do is put on some oven gloves,
and get.a piece of insulated wire. Attach one end of the wire to a ground
pin (look around on the circuit boards etc.) and poke the other end of
the wire under the suction cup until you hear a spark noise. Do it a few
times until you are super super sure everything is discharged, and even
then use a multimeter to check the voltages of everything your hands come
Btw, if you do this wrong, say hi to Jesus for me alright?
A flyback transformer in the monitor
generates a few kV that is used to accelerate electrons in the CRT to hit
the screen, and produce the pornographic images we all love to view because
no girl will talk to us. There should be at least two large leads coming
out of the transformer. One goes towards the suction cup thingy near the
front of the screen (thats the super high voltage one), another goes to
the rear end of the tube (should be more or less 0v).
Cut up the high voltage wire that goes
to the suction cup, and splice in a wire of your own. Be sure to insulate
the connection with CIA approved insulation materials such as paper
towels and sellotape. This wire will go to one side of the Jacobs ladder.
Follow the other wire coming out of the flyback transformer, and see where it goes to. Find a convenient place to solder a wire to. My monitor's wire appeared to go through a large variable resistor (for tuning the focus of your p0rn) which was connected to the pcb. I soldered my ground wire around there.
The 'ladder' was just a coathanger ripped
in half, bent to form two almost parallel rods, with the wires soldered
to each end. See it now? One lead from the transformer goes to one
rod, the other end goes to the other rod. It's the simplest circuit ever.
Just make sure the rods don't touch each other otherwise you might start
a fire that burns through your neighborhood killing poor innocent squirrels.
Please, think of the squirrels.
How do you activate the ladder? Just
make sure the monitor's power button is pushed in, plug the monitor into
the mains and turn it on. The first time I powered this thing up I was
pretty sure I would die... So I was extra cautious.
Turns out it worked fine and nothing went
up in smoke so I took the setup indoors for some pics.
The multiple 'thick' arcs that you see are actually caused by the relatively slow exposure time of the camera. Viewing the ladder IRL you will see a very thin arc moving up and down.
Movie that you must see to understand wtf is going on. (1.2mb, maximize it so you can see something). You'll need the DivX codec to watch.
As you can see, the arc moved upwards then reformed lower down as it should. Its kinda glitchy, but anyone who wants to put in the effort could easily 'tweak' the rod spacing to get a better show. Btw, after you have finished running the ladder and turned the monitor off, put on an oven glove and stick something metal in between the rods to discharge the cap.
I found the ideal gap between the rods was about 1cm for this particular monitor. I guess a nice old Sun 21" monitor would have a kickass transformer and make some really nice wide arcs?
More really cheap mods