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

Cool! Make sure you wear eye protection or even better flip the switch from a remote point.

Wes S

Oh would I love to put a few of those stickers on some machines at work!

Wes S

I will try to find an empty coke can, if so, I will try to crush one tonight. That's relatively easy and requires less energy.

If I make a strongbox from some piece of junk electrical enclosure lying next to my boat, I will try to shrink coins as well. I will keep you in mind.

i

Ditto

i

This sounds like the power supply for a very cool rail gun!

Bob

My recall of time spent in labs where we discharged large capacitor banks into spark gaps includes X-Ray exposure badges being worn - so you might want to limit the amount of "amusing sparks" you go around producing in the open...

The Variac on HV supply AC input is a standard technique for being able to charge things up slowly and not overload the supply. Standard operating procedure would be to start with it at zero, crank it up slowly while monitoring capacitor voltage.

Ecnerwal, that is exactly how it is done on this machine. Good point about x rays... I will have to read up on it... Energy of electrons that hit TV screens is 20 kV...

i

It would require about 4 times more capacitors... (16 kJ)

i

What happens if you try to crush a full Coke can? ;-)

Just exploded a very thin steel wire at 12 kV. About 936 joules. Explosion was as loud as a gunshot. I seriously regret forgetting to wear hearing protection.

i

As long as your experiments are performed in air at STP, X-rays will not be a problem. X-ray generation can become a problem when using vacuum switches, vacuum capacitors, or other high vacuum devices (Klystrons, HV vacuum tube rectifiers, or hard tube modulators) at high voltages. Film badges will not be necessary when working with your equipment and experiments.

Bert

Big Kersploosh! all over. It's been done, and filmed.

-->--

:^)

Thanks Bert... I exploded a wire today... It was LOUD... The sound was even sharper than a gunshot. I only have two more of such little steel wires...

i

I like the wood burning picture, seems very simple, though wet wood could explode under a pulsed discharge.

i

Bert,

Could you explain (in terms I might understand) why a vacuum makes a difference?

TIA

Harold

Hi Harold,

X-rays occur when charged particles (such as electrons) are accelerated to high velocities by means of a high voltage electric field and then rapidly decelerated by colliding with matter.

In air at STP, free electrons tend to frequently collide with air molecules or combine with neutral oxygen or water vapor molecules to form negative ions (called electron capture). The average lifetime of free electrons in air at STP is only about 11 billionths of a second. Because of collisions and electron capture, free electrons in air cannot reach velocities sufficient to generate potentially dangerous X-rays, even in the presence of very high voltages and high electrical fields.

In a vacuum, free electrons can be accelerated by the applied HV field without colliding with many gas molecules. They can be accelerated to much higher velocities before eventually colliding with an electrode or the walls of the container holding the vacuum. Higher electron velocities translate into higher energy X-rays. Voltages of 10-20 kV and above can generate "soft" X-rays, and higher voltages will generate "harder" (more penetrating and more dangerous) X-rays.

Bert

It's likely not, since most machines employ meter ranges that go 20 to 25% past their maximum operating range. I suggest you pull one of the capacitors and examine its nameplate rating, or get its part number and call Maxwell (I saw your caps nice orange color) to find out the rating. You'll not want to operate your capacitors past say 80% of their rating, if you want them to enjoy a nice long life, right?

Another suggestion: clean those insulators! Better yet, clean the whole machine! Dirt and grime may look right, and go well with a welder, but 20kV gear should be nice and clean, IMHO.

Now what does it take to use your supply to generate a very nasty EMP pulse?

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