Making lightning with a thin wire

[Ignoramus17570]

Just thinkin' of some fun uses of my thumper.

Let's say that I have a high voltage capacitor that I can discharge at
will. If I connect it to a thin wire (24 ga or so), say a foot of it,
and put through a several kilovolt/kilojoule discharge, would the exploding wire
create enough heat to ionize air sufficiently to create lightning
strike-like spark from the cap?

Another question, can such things be viewed with an autodarkening
welding helmet. (1/20,000th of a second darkening time)

i

 

[martin.shoebridge]

Just thinkin' of some fun uses of my thumper.

Let's say that I have a high voltage capacitor that I can discharge at
will. If I connect it to a thin wire (24 ga or so), say a foot of it,
and put through a several kilovolt/kilojoule discharge, would the
exploding wire
create enough heat to ionize air sufficiently to create lightning
strike-like spark from the cap?

Another question, can such things be viewed with an autodarkening
welding helmet. (1/20,000th of a second darkening time)

i

I think lightening is way up in the Megavolts....

 

[Martin Riddle]

Just thinkin' of some fun uses of my thumper.

Let's say that I have a high voltage capacitor that I can discharge at
will. If I connect it to a thin wire (24 ga or so), say a foot of it,
and put through a several kilovolt/kilojoule discharge, would the
exploding wire
create enough heat to ionize air sufficiently to create lightning
strike-like spark from the cap?

Another question, can such things be viewed with an autodarkening
welding helmet. (1/20,000th of a second darkening time)

i

Some researchers down south, use model rockets with fine wire attached and
attached to the earth to trigger lighting strikes when the conditions are
right. I guess if you have enough energy you can vaporize the wire.

Cheers

 

[Winfield Hill]

Ignoramus17570 wrote...

Another question, can such things be viewed with an autodarkening
welding helmet. (1/20,000th of a second darkening time)

Be careful: 50us isn't fast enough.

 

[Ignoramus17570]

I think lightening is way up in the Megavolts....

But it could work if the vaporized wire created ionized path.

I am trying to find a thin enough wire, and then I will give it a
try.

i

 

[Electroniker]

Ignoramus17570 wrote...

Be careful: 50us isn't fast enough.

While in college, I worked in an on campus instrumentation lab. Our
job was to build whatever it was that researchers needed. I was given
the task of designing an safe fuse and detonator for an
acetelyne/oxygen bomb developed by the US Bureau of Mines. It was
called a CERB (Controlled Electronic Rock Blaster).

The fuse consisted of a piece of #30 wirewrap wire strung between two
mounts. This was sealed into the gas mixture housing. The fuse was
considered safe since only a huge amount of energy could cause
ignition.

Ignition was accomplished by charging a large capacitor (5 uF) to 15
KV. This cap was the input to a triggered spark gap. The output was
the #30 wire in the gas mixture chamber. The cap was charged, arming
the circuit, and then the spark gap trigger by a thyraton, causing the
cap to be discharged into essentially a short.

The discharge event lasted less than 5 usec, in which time, the wire
would vaporize igniting the gas mixture. A combustion wave would
propagate down the cylinder, and at 100K psi, a shear plate would
release, sending a shock wave down toward the area to be "blasted".
The theory was that the shock wave could be more controlled, better
directed, and the blast would consume less energy than conventional
explosives.

This was one of the best projects I ever got to work on. The first
test was in a basement lab and we had no idea what the effect of that
kind of force would be. The room was destroyed. The shear plate
punched a hole in the concrete wall, all the lights were in shambles.
Later, a steel plate was used as the target and even this ultimately
had a hole abraded through it.

The first field test was also spectacular. The CERB was untethered,
and when detonated, shot straight up in the air like the rocket it was
with only the fuse and detonator wires to limit its flight.

Other labs were working on the approach as well. The highest energy
data point could never be replicated because the researcher lost his
lab in the experiment. Our work was directed by Thomas Blythe, whose
brilliant career was shortened by some tough disease.

Blakely

 

[[email protected]]

While in college, I worked in an on campus instrumentation lab. Our
job was to build whatever it was that researchers needed. I was given
the task of designing an safe fuse and detonator for an
acetelyne/oxygen bomb developed by the US Bureau of Mines. It was
called a CERB (Controlled Electronic Rock Blaster).

The fuse consisted of a piece of #30 wirewrap wire strung between two
mounts. This was sealed into the gas mixture housing. The fuse was
considered safe since only a huge amount of energy could cause
ignition.

Ignition was accomplished by charging a large capacitor (5 uF) to 15
KV. This cap was the input to a triggered spark gap. The output was
the #30 wire in the gas mixture chamber. The cap was charged, arming
the circuit, and then the spark gap trigger by a thyraton, causing the
cap to be discharged into essentially a short.

The discharge event lasted less than 5 usec, in which time, the wire
would vaporize igniting the gas mixture. A combustion wave would
propagate down the cylinder, and at 100K psi, a shear plate would
release, sending a shock wave down toward the area to be "blasted".
The theory was that the shock wave could be more controlled, better
directed, and the blast would consume less energy than conventional
explosives.

This was one of the best projects I ever got to work on. The first
test was in a basement lab and we had no idea what the effect of that
kind of force would be. The room was destroyed. The shear plate
punched a hole in the concrete wall, all the lights were in shambles.
Later, a steel plate was used as the target and even this ultimately
had a hole abraded through it.

The first field test was also spectacular. The CERB was untethered,
and when detonated, shot straight up in the air like the rocket it was
with only the fuse and detonator wires to limit its flight.

Other labs were working on the approach as well. The highest energy
data point could never be replicated because the researcher lost his
lab in the experiment...

Don't you just hate it when that happens!

What explosives did you use? Perchlorate and...???

Michael

 

[Ignoramus17570]

While in college, I worked in an on campus instrumentation lab. Our
job was to build whatever it was that researchers needed. I was given
the task of designing an safe fuse and detonator for an
acetelyne/oxygen bomb developed by the US Bureau of Mines. It was
called a CERB (Controlled Electronic Rock Blaster).

The fuse consisted of a piece of #30 wirewrap wire strung between two
mounts. This was sealed into the gas mixture housing. The fuse was
considered safe since only a huge amount of energy could cause
ignition.

Ignition was accomplished by charging a large capacitor (5 uF) to 15
KV. This cap was the input to a triggered spark gap. The output was
the #30 wire in the gas mixture chamber. The cap was charged, arming
the circuit, and then the spark gap trigger by a thyraton, causing the
cap to be discharged into essentially a short.

Pretty much what I did this evening. Same voltage even. It was
LOUD. OMG. What did you say?

The discharge event lasted less than 5 usec, in which time, the wire
would vaporize igniting the gas mixture. A combustion wave would
propagate down the cylinder, and at 100K psi, a shear plate would
release, sending a shock wave down toward the area to be "blasted".
The theory was that the shock wave could be more controlled, better
directed, and the blast would consume less energy than conventional
explosives.

That was used in some nuclear weapons also (blast directing foil onto
the secondary explosive).

This was one of the best projects I ever got to work on. The first
test was in a basement lab and we had no idea what the effect of that
kind of force would be. The room was destroyed. The shear plate
punched a hole in the concrete wall, all the lights were in shambles.
Later, a steel plate was used as the target and even this ultimately
had a hole abraded through it.

sounds like fun.

i

 

[Electroniker]

Don't you just hate it when that happens!

What explosives did you use? Perchlorate and...???

Michael

The actual explosive was just an acetylene and oxygen mixture, chosen
for its cheapness and ease of handling. The gases were injected into a
combustion chamber (6 inch x 3 foot cylinder). Shear plate on one
end, fuse on the other, gases in between.

One of the other pieces of equipment that we designed was an Ion
conductivity gauge which allowed the researchers to measure the speed
of the combustion wave as it propagated down the cylinder by measuring
the change in conductivity of electrodes inserted into the cylinder
down its length.

Blakely

 

[colin]

The actual explosive was just an acetylene and oxygen mixture, chosen
for its cheapness and ease of handling. The gases were injected into a
combustion chamber (6 inch x 3 foot cylinder). Shear plate on one
end, fuse on the other, gases in between.

One of the other pieces of equipment that we designed was an Ion
conductivity gauge which allowed the researchers to measure the speed
of the combustion wave as it propagated down the cylinder by measuring
the change in conductivity of electrodes inserted into the cylinder
down its length.

That can be quit a spectacular mixture, the mechanic at the local garage in
Bradford apparently complained about an acetylene leak one night, IIRC, but
was told just to ignore it, the next day there was nothing to be seen for a
considerable distance around where the garage used to be.

Colin =^.^=