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This is a question Home Science

Have you split the atom in your kitchen? Made your own fireworks? Fired a bacon rocket through your window?
We love home science experiments - tell us about your best, preferably with instructions.

Extra points for lost eyebrows / nasal hair / limbs

(, Thu 9 Aug 2012, 17:25)
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Don't try this at home kids
OK before I begin, does anyone remember the disposable flash cubes that you could fit on top on your camera in the halcyon days of the 80s?
For all you youngsters these were old school use once flashes that looked like this: www.hp.com/hpinfo/abouthp/images/flashcubes.jpg
They ran from the two 1.5v AA batteries in your camera and you often had to wait 2 minutes for the capacitors to charge before you could even use them. So back to the story:

One hot summers day a young skintagain was sat indoors during the blistering heat of an 80s summer holiday. The beaded door curtain was swinging and knocking in the wind. His bike had a puncture and he had the house to himself. He had already tried all the drinks in the drinks cabinet and was skulking round the house wondering what to do... When he suddenly spied a box of the aforementioned flash bulbs on the kitchen side and wondered "What if?"

Well I can absolutely tell you that plugging one of these into the mains is NOT a good idea. Whenever I see footage of the white heat of Hiroshima I am instantly transported back in time. The immense ball of white light gave me retina burns that lasted for two days. Pieces of the melted plastic casing were scattered throughout the lounge and the plug socket smelled like burnt cabbages for weeks.

The clean-up process was ahem.. "interesting" as I was only able to use my peripheral vision. And with the cunning skills that only a teenagers possesses I covered the burnt area of carpet with a pot plant. Surreptitiously placed smack bang in the centre of the room because that "won't look suspect"

(, Mon 13 Aug 2012, 14:11, 13 replies)
You had a power socket in the centre of the room?

(, Mon 13 Aug 2012, 14:22, closed)
I used the cable from the VCR and where it trailed across the floor the carpet melted
(, Mon 13 Aug 2012, 14:29, closed)
You had a VCR in the centre of the room?

(, Mon 13 Aug 2012, 14:36, closed)
Of course, his parents would get people round for drinks and they'd discuss it
it was the centrepiece of the room.
(, Mon 13 Aug 2012, 14:53, closed)
It really tied the room together.

(, Mon 13 Aug 2012, 17:32, closed)
I'm not going to go all Accord on this
as I'm sure you did do it and it certainly would have exploded. I'm intrigued as to why it should possibly have gone off any more brightly than normal before it went bang though?
(, Mon 13 Aug 2012, 14:57, closed)
Because of why it went bang, I expect.
It'll have been as bright as the power supplied to it, which wouldn't have been loads from the batteries compared to a mains supply.
(, Mon 13 Aug 2012, 16:19, closed)
Someone's never played with electronics
Find an LED, an AA battery and a 9v battery. From your experiments with these you should easily be able to figure out why putting 240v through it would be so bright.
(, Mon 13 Aug 2012, 17:00, closed)
Except that's not how a flash bulb works.
A single-use flash bulb is a one-shot chemical reaction. IIRC. It works nothing like an LED or even an incandescent filament. In any case the bulb runs off a capacitor discharge, not the power source directly. You're more likely to make the capacitor go bang.
(, Mon 13 Aug 2012, 17:07, closed)
and that would in no way
generate an enormous electrical flash and possibly result in all flashes in the cube going off at once?
(, Mon 13 Aug 2012, 23:25, closed)
Unless I'm mistaken
and I'm not, because I've inadvertantly stuck my fingers on the terminal of a flash capacitor, the flash uses around 15,000 volts, whereas mains uses 240.

The ampage is the reverse, mains is far higher than the flash.

Would 240 even be enough to set off a flash? I'm quite sure it would mightily fuck everything up, so going pop would make sense, but would it be a very bright pop?

(edit) answers below seem to say it wouldn't make any difference.
(, Tue 14 Aug 2012, 8:45, closed)
Pedant mode
By the 80's these cubes didn't use batteries, they had a much more exciting fulminate detonator that set off zirconium shreds. The fulminate was set off by a plastic or metal prong that came up from the camera.

Looking back on it they would of made fantastic home made bomb detonators.
(, Mon 13 Aug 2012, 18:42, closed)
A nice story, if a little elaborate
Any of the flash bulbs and flash cubes used shreds of flammable metal such as magnesium, generally set off by a very small thin wire that got hot when a current was passed through it. Once the ignition filament was activated it burned out so no more current passed through it. The intensity of the burning magnesium or what ever was not dependent on the voltage of the power supply. The small and brief current that passed through the ignition filament would not have caused the VCR cord to burn the rug.
(, Tue 14 Aug 2012, 2:06, closed)

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