"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.

So I did it, and it went instant POF, flash of light, small cloud of  smoke, 
smell of ozone and the armature flew out of the casing onto the floor.  It 
was too hot to pick up.  No spin.  The brushes were all twisted and 
blackened and the commutator was scorched.

And in that instant, I knew my friend had lied.  At the time, I was about 10 
or 11.

Postscript:
Amazingly, the armature winding didn't burn out.  Although the bearing face 
that had held one end of the shaft in place was completely gone, and the 
brushes were wonky,  if you held the shaft of the armature in the right 
place with your fingers, it would still spin on battery power.

I kept it for a long time as a special memento.

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