"Arttu Voutilainen" <bli### [at] removethiszbxtnetinvalid> wrote in message 
news:47337108$1@news.povray.org...
> Eero Ahonen wrote:
>> Brian Elliott wrote:
>>> "Alain" <ele### [at] netscapenet> wrote in message
>>> news:4731f3f7$1@news.povray.org...
>>>> Once when playing with a small speaker, I pluged it in a transformer
>>>> and was prety unimpressed by the feeble low hum I got, so, I plugged
>>>> it directly into the wall socket, hoping for a loud hum. Use a regular
>>>> electrical plug, hook the speaker whires in to it, plug it in. Instant
>>>> POF, flash of light, small cloud of smoke, smell of ozone and burnt
>>>> metal, bursted speaker's dome. The coil's whires got vaporised.
>>>> At the time, I was about 10 or 11.
>>> I did the same to one of those tiny 3-volt DC motors, like the cog-ended
>>> ones that are in battery-powered toys.  A friend bragged at school he'd
>>> plugged one into the mains, and it went really incredibly fast and was
>>> really hot afterwards.
>>>
>>
>> Every time I read these I feel more and more sorry for myself for NOT
>> doing something that stupid (and cool :p) as a kid.
>>
>
> Yeah, me too.
>
> Guess I have still some time left to do something cool with elec ;)

Something cool to do as a bigger kid.

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)

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...

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".

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