5/16/2002: Quarter shrinking machine
 

http://cellar.org/2002/quarter1.jpg

http://cellar.org/2002/quarter2.jpg

OK, not exactly a quarter shrinker, but a quarter re-sizer; the quarter gets thicker as its diameter shrinks.

But what's wild about this is how it's done: by creating a massive magnetic field. From the site:

The quarter shrinker uses a high voltage capacitor bank and a triggered spark gap to apply up to 125,000 amps through a small work-coil of #10 AWG magnet wire which surrounds the coin. Once the spark gap is triggered, a current of over 1 million amperes in induced into the coin, and the interaction of the induced magnetic field and the field from the coil cause the coin to shrink radially-inward. At the same time, the work coil explodes into copper shrapnel, and then into a 8" ball of plasma. This all occurs in about 20 millionths of a second. The experiment is done under a bulletproof Lexan blast shield. It's a very energetic and dangerous process - don't try this at home folks... :^)

The guy also has a huge tesla coil and a lot of really wild images featuring that. Here's his page (with images that load pretty slow):

http://navarrone.com/tesla/tesla4.html

But the real question...

Is it still legal tender?

cool
 

This brings to mind a device I've always wanted but cannot find since I never seem to think of it when the opportunity presents itself.

I want one of those electrical devices which consist of a coil, transformer, emitter and rabbit-ear antennae.
It produces a spark which climbs the antennae slowly or quickly depending on the power of the transformer and is a staple of old Frankenstein movies. If I had the name I might actually find one. Someday.

Anyone know what I'm talking about?

Brian

I know exactly what you're talking about, as we had one in one of my science classes I took in high school. Alas, I have no fucking clue what it's named :)

Agreed, however, that they are indeed very cool. One could keep their kids in line with it - "Eat your peas or you get the shocky." :)

So what good are ya? ;)

Seriously, how on Earth do I Google that one?

Brian

Re: cool
 

They are called a "Jacobs Ladder". I had one.

Charlie

Weeeeeeeeee!

http://www.amazing1.com/voltage2.htm

Go there to buy plans, a kit and even a pre-assembled one.

I had a friend in High School in the early 70's who was kind of a Dr. Science type. He was always building things and I would help him out sort of like an apprentice. He built several lasars (and this was way before you could buy them at the office supply store as a pointer) and every manor of gadget. He made all kinds of explosives like dynamite and pipe bombs with electronic ingniters.
Back then it was just good clean fun. It was then that I found out what a can of diesel fuel and a 50 lb sack of fertilizer could do. WOW

Once we made a tesla coil. He used a neon sign transfomer as many of them do and he made his own capacitors out of large jars of salty water with tinfoil wraped around the outside and wires hooked up to them. I'm no electical engineer so I don't understand the concept. Anyway the tesla coil we built was very powerful and you could stand about 10 feet away from it holding a flourescent light bulb that wasn't hooked up to anything and it would light up. Finally the neighbors on all sides of his parents house complained as tesla coils can knock out your tv reception and they were getting pretty pissed off.

We lost touch after we went to college and I made contact with him about 10 years later. Found out he got a BS in Physics and a Masters in Chemical Engineering fro Clemson University but didn't do anything with it. Instead he worked on cars at a garage and became a born again Chrisian and went on missions to south America spreading the word.

I feel so much safer knowing he is out there doing missionary work!

was there one of those in one of my classes, or am i just reliving a scene from powder?

Transmitter
 

Be aware that Jacob's Ladders are also spark gap transmitters. They are quite noisy over a broad range of the RF spectrum and may cause noticeable interference especially to low power devices like cellphones and WAP. For what its worth there are internet reports of people getting fined by the FCC or the local equivelent.

That being said they are wicked cool and are simple to make. :D

I had one of those things
 

I used a big neon sign transformer and two pieces of coat hanger and yes, they work just like in the movies.

We also rigged it so one wire charged a metal plate, and the other hung over the plate. You could place various unsuspecting objects on the plate, and zap the bejesus out of them, for minutes at a time. This was great fun with the lights off. One of my favorite things to zap was chunks of ice, the spark would run all over eroding it down to just water, lighting the ice beautifully.

Important safety tip: Do not allow wet hands to get anywhere near the wires.

Re: I had one of those things
 

Another important safety tip: at those voltages it doesn't matter whether your hands are wet or dry.

Yes and with a Tesla coil you can walk in the room and hold up a finger and an 8 ft spark will bounce from the coil to you finger.

Funny, I have never been able to father children after that trick!

Chris in Houston