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What to look for in an old NST

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HM_Murdock

Fri Aug 20 2010, 05:45PM

Registered Member #3075 Joined: Fri Aug 06 2010, 02:44PM
Location: Athens, GA
Posts: 148

GREAT SUCCESS!! (done in my best Borat voice)

I have 4 NST's...all France Formers

I have 3 that are 15kv/30ma, and one that is 9kv/30ma!

The guy at the shop even rolled me off about 8 feet or so of HV wire...

Now just need to do some studying on safety with these so as not to kill myself, and then I will start with a simple Jacob's Ladder...

quicksilver

Fri Aug 20 2010, 06:44PM

Registered Member #1408 Joined: Fri Mar 21 2008, 03:49PM
Location: Oracle, AZ
Posts: 679

{total opinion -simply my limited experience}
I think that the France is one of the best you can lay your hands on & I've had a few of a very wide variety. When I started making TC I abused the HELL out of them, I'm sure.
I would test them; then lay one aside and use that one: keeping the rest for differing projects, ect.
....WELL DONE!

HM_Murdock

Fri Aug 20 2010, 08:16PM

Registered Member #3075 Joined: Fri Aug 06 2010, 02:44PM
Location: Athens, GA
Posts: 148

well, I built a dirt simple Jacob's Ladder with the 'little' one

Holy crap, this thing scares me!! Sounds and looks VERY lethal...

The power is cool as all get out, but that "oh, how cute...it's a little 1CM purple corona and arc" from my FBT driver has been replaced with with a fiery, loud, orange BRRRRZZZAPP!! sounding arc...

What's the difference...is is just more current that is doing it, is it the nature of an NST Vs. an FBT, or what? I kinda like the hissing, purple arc I get with my FBT better...sounds like like lightsabers rubbing against each other, where this thing sounds like an electric chair!

1282335329 3075 FT94871 Nst Jacobs Ladder

ScotchTapeLord

Fri Aug 20 2010, 08:28PM

Registered Member #1875 Joined: Sun Dec 21 2008, 06:36PM
Location:
Posts: 635

The sound is because it is running at 60 Hz frequency and the appearance is because it is running a much higher current.
You have three identical NSTs? Parallel them! Just be sure to phase them properly... and to stand way back when powering them up. Now that would be one hell of a Jacob's Ladder!

Jiffycoil

Fri Aug 20 2010, 09:15PM

Registered Member #2524 Joined: Wed Dec 09 2009, 06:29AM
Location: Johns Island, South Carolina
Posts: 23

And so it begins.

HM_Murdock

Fri Aug 20 2010, 10:36PM

Registered Member #3075 Joined: Fri Aug 06 2010, 02:44PM
Location: Athens, GA
Posts: 148

So, is it possible to reduce the frequency and current and keep the high voltage? And if so, what would be the result in the arc?

Adam Munich

Fri Aug 20 2010, 11:41PM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

It isn't possible. These transformers are designed to run at 60 hz, which is why they are big and heavy. FBT's run at 15,000 hz, which is why they are small and puny. You can reduce the current by putting a limiting "resistor" in line with them, like a 40W lightbulb, but the frequency can't be changed.

To lower the voltage, use a variac. Also, a NST is likely not lethal, but it is dangerous (and painful) to get shocked by one.

Also again, Have you tried frying a CD yet? And try making a huge jacob's ladder. I have this one on display in my front room. People always are shocked (no pun intended) when I turn it on. The cat will also just sit there and stare at it. Smart enough to not touch though! Thick aluminum wire from craft stores works very well.

How much did you end up buying those for?

HM_Murdock

Sat Aug 21 2010, 01:16AM

Registered Member #3075 Joined: Fri Aug 06 2010, 02:44PM
Location: Athens, GA
Posts: 148

Thanks for the info...one question...what happens to the arc if I reduce the current? I know theoretically it should make the output less deadly...but I wonder what would happen to the characteristics of the arc...

And yes, I did in fact fry a CD tonight...cool to watch, nasty to smell...lol. It also melted to the cutting board I had it laying on.

Will have to get some of that aluminum wire...that's a cool looking ladder you have there

And they cost me all of $0. The guy at the shop I went to just walked over to his bench and pulled out 4 of them...had a whole pile of them under there. Just gave them to me.

Mike

Sat Aug 21 2010, 01:24AM

Registered Member #58 Joined: Thu Feb 09 2006, 05:40AM
Location: Tri-Cities, Washington, US
Posts: 317

Great job there. Four working NST's for free is an AWESOME find. I hope to see some more projects soon.

Adam Munich

Sat Aug 21 2010, 01:52AM

Registered Member #2893 Joined: Tue Jun 01 2010, 09:25PM
Location: Cali-forn. i. a.
Posts: 2242

HM_Murdock wrote ...

Thanks for the info...one question...what happens to the arc if I reduce the current? I know theoretically it should make the output less deadly...but I wonder what would happen to the characteristics of the arc...

Likely, the arc will get more "sparky". Blue/white, crackling, etc. Not very good for a ladder.

Another fun thing to try is kirlian photography. Take 2 pieces of plastic transparency sheet and place it over aluminum foil. Hook that foil to one terminal of the transformer and place that on a piece of plastic. Next, place a piece of paper film over the glass. Put a metal object or a leaf etc atop that, and connect that to the other terminal. When the transformer is turned on, "Lightning" forms. Often the quicker the transformer is turned on and off, the better the picture, so put it on a push-button.

You want to use High speed film.

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