Brian Elliott wrote:

> Rat the Extra-High-Tension transformer out of an old junked CRT-type TV 
> or monitor.  (That weird-looking gangly thing covered in large amounts 
> of black wax, with the *heavily" insulated wire from its top, that plugs 
> into the back of the Cathode Ray tube)
> 
> Using an ohmmeter, you can determine which wire is the other side of the 
> HT coil, and which wires are the low-voltage coil (they'll have less 
> resistance, and maybe even a centre-tap point)

Um... this sounds a little disturbing...

> Fashion up a convenient 555 timer circuit on a 12-volt plugpack.  Tune 
> it to about 16 kHz.  (or just go for "high squeal like a TV" set).  
> Buffer its output with either a single-ended, or for more efficiency, a 
> push-pull power transistor output stage.  A naked 2N3055 will do fine, 
> but you can use a smaller power transistor if you bolt it onto a 
> heatsink.  Remember to put reverse-biased power diodes across the output 
> transistor to soak up the back-EMF from the primary coil or you'll 
> probably fritz your transistor pretty quick.
> 
> Eg. Assuming you have an NPN power transistor with emitter to Ground, 
> bung its collector in series with the low-Volt primary winding to the 12 
> Volt rail.  Now, you need...

...I have no idea what you just said...

> One clear 240-Volt tungsten incandescent bulb, but with a popped 
> filament. It needs to have enough filament intact that there isn't too 
> big a gap.
> 
> Hook the bulb up to the HT side of the transformer, turn the whole 
> kaboodle on, and with a little luck, the bulb will display a lovely 
> pinkish-violet ionised argon "flame" between the filament ends.  It'll 
> should have enough energy to make the filament red hot and the glass hot 
> above the convective "flame".

Erm... I think I'll just stick with my plasma ball at home. ;-)

[EDIT: Just as soon as I can find the damn power supply...!]

Did you know, if you balance a metal object on the glass, and hold your 
finger just the right distance from it, it produces a continues bright 
blue spark? However, be careful; I actually burnt my finger this way...

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