The Jacobs Ladder thread

[dnar]

Seeing as discussions regarding Jacobs Ladders keep popping up, I thought they deserved a dedicated thread.

Post your Jacobs Ladder stuff here.

 

[laser83]

Random topic, it's a horror that has spawned many great series as result. I once talked to a teacher that had studied the movie. According his analysis it is apparently based off the Tibetan of the dead as a focal point. Anyway the movie is supposed to made sense when that book is properly understood as the screenwriter based the idea off of it.

 

[Toke]

Looks cool, would be fun to build sometime.

 

[laser83]

Ha, you were referring to the electronic device (your link didn't work). Jacob's ladder




http://en.wikipedia.org/wiki/Spark_gap#Visual_entertainment

 

[dasraiser]

awesome ladder dnar :bowdown:

wonder y the spark is always moves up and away from the source and if its the same reason a rail gun works :thinking:

 

[HIMNL9]

awesome ladder dnar :bowdown:

wonder y the spark is always moves up and away from the source and if its the same reason a rail gun works :thinking:

No, a rail gun uses magnetic field ..... jacob's ladder arc is "climbing up" just for the combination of 2 things ..... first, the arc produces ionized air path, that is more conductive, and second, the arc also heat this air, that flows up, so the arc path tend to follow this air current, "climbing" up the ladder ..... also, once the arc is established, the path inside it have lower dielectric resistance than the bare air, so it still shoot in the same climbing path, instead to just extinguish and re-shot at the bottom, where the electrodes are more closes (this, ofcourse, if the frequency is high enough for keep the arc shooting ..... under a certain frequency, there's no climbing arcs, just sparks at the bottom) ..... this until, ofcourse, it arrives in a point where, also with the ionized path, the voltage cannot maintain the arc (for this reason, sometimes, big units have curved ends wires, at the top, so the distance increase and the arc extinguish more easily) ..... at this point, it extinguish, and restart where the electrodes are more closes, at the base, and all restart.

 

[Tech_Junkie]

Nice work. How far was the laser away from the ladder? I'd like to put one right under bottom of the ladder, between the rails where the arc starts. But I've heard electronics and ladders dont mix. I wonder if the laser would survive that close. :thinking:

 

[Toke]

It looks to me like the laser is elsewhere and "start point" of the beam is a plastic mirror.
(My impression may be biased by finding the idea of a laser between the electrodes absurd.)

ETA: The ladder will give out a lot of EMP, tinfoil shielding and twisted pair cables will help.
I do not know how much EMP or help.

 

[Tech_Junkie]

Of course its absurd. Thats what makes it original, and Steampunk. I've decided to use these stand offs instead of glass insulators, and the mirror is a good idea.

 

[Toke]

You misunderstand, I like the look of sparks intermingled with a laser beam.
It is the laser module, usually made of metal, that I would find absurd to place between the electrodes.

There were a mention of some start assistance involving a 3. electrode at the bottom, right between the others and connected to one with a MOhm resistor.
I wonder if one could make a module that could survive such dual application.

 

[Tech_Junkie]

There were a mention of some start assistance involving a 3. electrode at the bottom, right between the others and connected to one with a MOhm resistor.
I wonder if one could make a module that could survive such dual application.

I doubt it. :tsk:

I'm working on a ZVS driver that should bring the mAs up enough I should not need a 3rd electrode. I'd hope not anyway. Those stand offs are over $30 a pair, and they only sell pairs.

 

[Toke]

I doubt it. :tsk:

Well, I can imagine lots of ways it could go wrong.
Better stick with the (plastic) mirror idea.

 

[00Giorge]

I used to build ladders with neon sign transformers for a Jaycee's halloween haunted house every year, I had 2 @ 7500V and 1 @ 50,000V, the 50,000 I borrowed from a friend that owns a sign co.

I was always told not to have any electronics in the same room, that they could be ruined from the effects of ladder, unless the ladder was encased in glass. That advice came from an electronics prof. at a college I went to. He used to build tesla coils and ladders, I can't remember what he exactly said but it was kind of an emp effect due to +ions and it would kill circuit boards unless properly sheilded.

Sorry I don't have any pics!

 

[DashApple]

Hey ,

Both My ladder Builds -

Pics is the setup Now for the video below , Its 4 MOTs , 2 as ballasts and 2 as running mots it produces 4.2kv @ 500 - 600 ma and draws 2.5kw of the Mains (sorry for pic quality)

YouTube - Microwave Transformer Arcs

YouTube - MOT arcs with resonant caps

 

[Tech_Junkie]

Damn, those are some insane arcs.

 

[Cyparagon]

electronics in the same room, that they could be ruined from the effects of ladder, unless the ladder was encased in glass.... emp effect due to +ions and it would kill circuit boards unless properly sheilded.

Since when does glass shield against EMI?