Things that go boom? Need to present to some kids

Hi

Every year I teach a class in 7th grade about electronics and space stuff

I normally end the presentation with a reverse power capacitor that goes boom, just so they at least get excited about that.

But, any other component that makes a large boom? (I would like to avoid the cap, since it spills electrolytics and smells bad

DPAK2 FET, with 30W disipated? Tantalum reverse biased?

Other?

Thanks

Klaus

Reply to
klaus.kragelund
Loading thread data ...

Dump a big cap or a biggish battery into a resistor?

formatting link

Or just AC line voltage.

Makes a controllable bang and smoke.

--

John Larkin         Highland Technology, Inc 
picosecond timing   precision measurement  

jlarkin att highlandtechnology dott com 
http://www.highlandtechnology.com
Reply to
John Larkin

Burn up a speaker ?

Reply to
Rheilly Phoull

----------------------

** Been there, done that.

Even using DC, its slow, boring and smelly.

..... Phil

Reply to
Phil Allison

What about the flour, candle, paint can, grain dust explosion example? I'd think its safer than tiny parts flying around. Just the lid will fly up and hit the ceiling.

Cheers

Reply to
Martin Riddle

Iron wire. Sparks!

Cheers

--
Clive
Reply to
Clive Arthur

I have always had great luck using a 1/4 watt carbon film 1K Ohm resistor on 120 VAC.

Back in my my audio days, we would connect up the 1K resistor to the amplifier load bank and so when the tech would fire up his bench for the day and the first amplifier, he would get a swell surprise. Adding a firecracker to that would REALLY get a response !

Kids also love Jacob's Ladders.

Reply to
boB

I thought it was a 1/2 watt, but anyway, it was wired in the big Weller soldering iron, when it smoked, what smoked and what was it's job?

Mikek :-)

Reply to
amdx

Resistors across the power line is a good trick. An Instructor in AF electronics school liked to connect one across the line in an AC power plug and tell the student to plug it in. Woke everybody up.

Reply to
gray_wolf

uff

es boom,

id the

Steel wool and a small firecracker?

Reply to
gray_wolf

Maybe launch a rocket? You could give specs on the electronic igniter circuit and ask how many AA batteries in series and/or parallel.?

George H.

Reply to
George Herold

As a I kid I enjoyed 'welding' with some 30-50mF cap, power supply and aluminum wires or steel wool. Not a big boom, but a lot of nice sparks.

--
mikko
Reply to
Mikko OH2HVJ

On a sunny day (Thu, 24 Oct 2019 12:28:17 -0700 (PDT)) it happened snipped-for-privacy@gmail.com wrote in :

300 W amp and big woofer, some sound track. Other noises possible too. Kids will find a use for that, not very dangerous.

In my school days I scored a big 220 V flash bulb, edison base, screwed it in in pace of house normal light bulb. Just wait until somebody switched on the light,,,

Reply to
Jan Panteltje

My kids always enjoyed the steel wool and 9V battery demonstration.

formatting link

Reply to
DemonicTubes

Typical trick is pass an inductor around room one way, and a battery around the other way.

Reply to
Robert Baer

On Oct 24, 2019, snipped-for-privacy@gmail.com wrote (in article):

When I was a kid (old enough to play unsupervised), one simple thing I did was to explode copper bridge wires underwater, in a half-filled fish tank. The bang could splash a lot of water onto the floor.

The equipment consisted of two insulated solid #14 (1.8 mm) copper wire pieces about a foot long clamped in parallel using some wood and screws. The far ends were stripped bare, and had a bit of #36 (0.127 mm) wire bridging the two #14 wires, which were connected to 115 Vac power via a large knife switch.

No, the 15-amp circuit breakers never popped - the bridgewire blew too fast.

Joe Gwinn

Reply to
Joseph Gwinn

I'm surprised no one's mentioned these little gizmos:

formatting link

--
This message may be freely reproduced without limit or charge only via  
the Usenet protocol. Reproduction in whole or part through other  
protocols, whether for profit or not, is conditional upon a charge of  
GBP10.00 per reproduction. Publication in this manner via non-Usenet  
protocols constitutes acceptance of this condition.
Reply to
Cursitor Doom

Thank you all for the comments

I used the shorted cap for welding/sparks, a small speaker at DC to show how sound sort of works and especially the 1k resistor at mains, which gave a good loud effect

I normally reverse bias a cap, but we were inside, so too much mess doing that

Cheers

Klaus

Reply to
Klaus Kragelund

A line powered flash bang would be too much? Bet it get their attention. ;-)

Reply to
gray_wolf

Blasting cap?

Reply to
gray_wolf

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.