The HELL MACHINE works!!! Was Ground tester or Hypot with 1/0 welding cable?

This is in regards to a thumper that followed me home last week. A thumper is a machine that makes high voltage capacitor discharges of thousands of joules, to find faults in underground buried cable. Mine is designed to deliver up to 4,062 joules, or approximately the energy carried by bullets from a burst of assault rifle fire.

See

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I thought that it was not working.

Today, a local luminary in the field of coin shrinking, Lichtenstein figures, and other fun high voltage things visited me and my thumper machine. I am not mentioning his name out of respect for his privacy, and feel very highly about him.

Anyway.

After I dragged its two pieces into my garage, we looked at the machine and opened up the covers. Some interesting things came to light.

  1. It was a 25 kV DC machine, with two contactors: a safety grounding contactor to ground the caps when power is off, and the thumping contactor to connect capacitors to output cable.

2.It has a variac for varying output voltage of the high voltage transformer. The high voltage is rectified by a center tapped rectifier (two diodes).

  1. It has a limiter arrow on the voltage display that causes the output contactor to close when capacitor voltage reaches the limiter.

  1. It also has a DISCHARGE button that can cause the discharge contactor to close at operator request.

  2. My machine did not work because the limiter (whose purpose I did not understand) was set to zero.

After he left, I wired up the machine and tried to use it. I made a primitive spark gap out of two large copper pieces. As it turned out, it works great. It charges the caps and when it reaches the preset voltage, it discharges into a spark gap.I only tried it at up to 10 kV.

Its output of 4k joules is supposed to be enough to shrink coins.

i
Reply to
Ignoramus7016
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Shrink coins?

Explanation, please.

Harold

Reply to
Harold and Susan Vordos

See Bert Hickman's highly instructive page

http://205.243.100.155/frames/shrinkergallery.html He showed me his shrunken coins, that was amazing. My machine can roughly shrink a quarter to a size of nickel, his can shrink it even less.

The energy that my thumper can attain is roughly equal to dropping one ton of weight, from the height of 1.5 ft.

i
Reply to
Ignoramus7016

This was certainly impressive and informative. I find high current and high voltage effects fascinating. The test sets I design will generate up to about 100,000 amperes AC for several tenths of a second, but the only effects I have seen are jumping cables and vibrating metal objects in the magnetic field. Thanks for the informative link.

Paul

Reply to
Paul E. Schoen

Thanks for the link, although I'm somewhat a skeptic. I didn't read all the information, so I may be bringing up a subject that was well addressed. In my mind, the laws of physics dictate that metals will occupy a given amount of space----a result of their atomic structure. In other words, their specific weight isn't up for grabs, it's a constant. I'm having a hard time imagining that coins shrink unless they lose weight in the process, or one of the dimensions is increased. Are the coins thicker than they were before being shrunk? Please bear in mind I'm not an educated person------I was lucky to escape high school by graduating.

There are mechanical presses that are capable of delivering tonnage that makes that look like nothing, and they don't have the ability to compress metals, at least as I understand it. I am impressed with the power of the thumper, but I still have my doubts about shrinking metals. with the exception of my comments, above. Otherwise, seems to me you could duplicate the specific gravity of gold that way. The way I understand it, you can do that only by creating gold, or an alloy of other elements that, combined, equaling the specific gravity (19.3. Platinum and something, for example). Am I missing something?

Harold

Reply to
Harold and Susan Vordos

Hello Harold

One of pix explains what happens:

"The thickness proportionally increases as its diameter is reduced. A shrunken coin's volume and mass remain the same, so its density remains unchanged. There's no "Honey, I Shrunk the Kids!" magic involved in coin shrinking."

As far as i know metals can be compressed for a short time using high explosive lenses, the mass remains the same but the density is increased for a few milliseconds.

Best Regards Tom.

Reply to
azotic

How about before and after pictures along with the set up prior to 'thumping'?

Curious minds need satisfying.

Wes S

Reply to
clutch

I remember, you are in the circuit breaker testing business...

i
Reply to
Ignoramus17570

The coins become smaller in diameter, but thicker, the volume stays same.

Electric current and magentic field acts like a press, changing form but not volume.

Yes, there is no magic like in Superman movies, there are very strong forces that change the shape of the coin and that's all.

I will try to shrink some coins (I have a small amount of magnet wire, which is used up on every attempt due to coils exploding) and if it works, I will mail one to you. I will need to make a box out of 3/4" plywood to contain flying coin shrapnels

Reply to
Ignoramus17570

I will try to do something... I need to get some 3/4" plywood to make a box to contain parts of coils that would fly like shrapnel. Will try to whip something up this weekend.

i
Reply to
Ignoramus17570

Igor,

You may want to use steel or aluminum plate on the inside of the box, since high velocity coil fragments tend to shred wood and the blast tends to blow wooden boxes apart. The most dangerous coil fragments will be ejected radially from those areas of the winding that are just above the coin. Also, position yourself at right angles (i.e., along the coil's rotational axis), and distance is your friend. An alternative night be to place sandbags all around the containment box.

Don't underestimate the danger posed by these little coil fragments - they've been measured up to 5000 fps on higher power coin shrinking systems.

Bert

Reply to
Bert Hickman

Bert, thank you for this advice and also for visiting and helping me figure out howw this machine works. As well as for pointing out that strain relief damage is inconsequential.

I am very grateful.

Thanks. I will see what is the best and most sensible thing to do to put something safe enough together.

i
Reply to
Ignoramus17570

5Kfps??!?!? Holy crap! A typical factory issue round out of a .30-06 (Hardly anybody's idea of a "toy" gun) is only clocking about 3Kfps! Even handloaders "pumping it up a bit" don't go too far beyond 3200fps.

I'm afraid to do the math to figure out the energy a typical 150 grain .30-06 bullet would have at 5Kfps! Talk about "red mist"...

Reply to
Don Bruder

Bert, I have a junk "electrical enclosure" that was used for an outdoor starter, it is a box made of painted steel that is quite heavy, maybe 3/32" thick or even 1/8". I will make pictures tonight, I think that it will be a quick solution to the problem.

i
Reply to
Ignoramus17570

Don, if I recall correctly, we share interest in guns. So let me throw in some numbers.

The maximum voltage on the scale of this thumper is 25 kV DC. I have not tried reaching this voltage, or anything close to it, yesterday, but let's assume that it is a 25 kV machine.

Its capacitance is 13 uF (a little bit more, like 13.37) measured with my Amprobe multimeter.

According to formula E = Cv^2/2, the energy in this machins is 4,062 joules.

Now consider a powerful rifle such as 30-06. Its bullet weighs 10 grams and flies out of the muzzle at 850 meters per second.

The energy of this bullet would be 0.010 * 850*850/2 = 3,612 joules.

So, the energy released by my thumper is greater than that in a 30-06 bullet.

i
Reply to
Ignoramus17570

This btw..is the same documented feature of the M67 hand grenade of current deployment. A coil of wire that is exploded to product fragments and has an effective range of 15 meters

Gunner

"Aren't cats Libertarian? They just want to be left alone. I think our dog is a Democrat, as he is always looking for a handout" Unknown Usnet Poster

Heh, heh, I'm pretty sure my dog is a liberal - he has no balls. Keyton

Reply to
Gunner

maybe this......

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martin

Reply to
martin griffith

that was hilarious!

i
Reply to
Ignoramus17570

Marvelous!

Gunner

"Aren't cats Libertarian? They just want to be left alone. I think our dog is a Democrat, as he is always looking for a handout" Unknown Usnet Poster

Heh, heh, I'm pretty sure my dog is a liberal - he has no balls. Keyton

Reply to
Gunner

Thanks, Tom. I read the link in haste-----and missed some of it----reading only that in one instance, there was some thickening around the rim area. I assume, after reading what you posted, that in that instance the coin shrunk disproportionately, but they all get thicker. I should have spent more time reading, but I'm spread thin. sigh!

That makes sense. The forces that keep the atom together are known to be quite powerful. You can bump them, but not permanently deform them. Those electrons demand their space.

Harold

Reply to
Harold and Susan Vordos

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