Terminals of Neon Transformer!!!

Thread Starter

steven2410

Joined Jul 7, 2014
16
Hi everybody!
Hi everybody!
I'm on the final step of completing my tesla coil. Bassically i have every components ready, except the neon sign transformer (9000v, 30ma). It has 5 terminals on it, 3 labeled G,H and N (Ground, Hot and Neutral), the other two do not have any label on. I want to make sure i got it right that is the inputs are the labeled ones right? The other 2 unlabeled terminals are output of the transformer ? One more thing. Is there anyway i can test out to make sure the transformer is working correctly before hooking it up with the rest of the coil? It originally had a GFCI (ground fault circuit interrupter) built in, but i have removed it in order for
 

Kermit2

Joined Feb 5, 2010
4,162
quick check
hook your meter to secondary. set for AC volts highest range.
hold neutral terminal on one end of AA battery and brush hot wire back and forth lightly on other battery terminal.
You should see 100 v pulses approx.
 

#12

Joined Nov 30, 2010
18,224
It kind of depends on how clever you are.
9000V @ .03A is 27 Watts
27 watts coming from a 120 volt wall outlet requires about .23 amp.

Install a 1 amp fuse on to where you think the primary winding is.
Plug it in. If you were wrong, the fuse will fail.
If you were right, the circuit will work.

So...that's one way to test this.
 

DerStrom8

Joined Feb 20, 2011
2,390
I'm surprised nobody has asked for a photo yet :p

Could you post an image of the NST? It will definitely help. You can usually tell the outputs from the inputs based on either the insulation thickness (if the wires are insulated), or the large bushings on the outside (if the outputs are bolts).
 

shortbus

Joined Sep 30, 2009
10,045
I'm surprised nobody has asked for a photo yet :p

Could you post an image of the NST? It will definitely help. You can usually tell the outputs from the inputs based on either the insulation thickness (if the wires are insulated), or the large bushings on the outside (if the outputs are bolts).
I'm surprised no one has said, " if you have to ask, maybe you shouldn't be messing with it". Not knowing input from output on a neon transformer sounds like a 'Darwin award' candidate in the making.
 

DerStrom8

Joined Feb 20, 2011
2,390
I'm surprised no one has said, " if you have to ask, maybe you shouldn't be messing with it". Not knowing input from output on a neon transformer sounds like a 'Darwin award' candidate in the making.
Shortbus, that is an excellent point.

I hope the OP has adult supervision, preferably someone who knows CPR. I know everyone always says this, but in this case it's very true. You're playing around with life and death.
 

#12

Joined Nov 30, 2010
18,224
True. At some time on this site, I think I said I wouldn't work on anything over 208-230 unless I had a helper available to re-start me. I guess we've had so many rather smart people here lately that we got complacent.
 

DerStrom8

Joined Feb 20, 2011
2,390
I know high voltage Tesla coil is no joke. But I really want to build one. I mean the best way to learn something is to build it right?
In some cases, yes, but when it comes to Tesla coils you really MUST know what you are doing. You may not get a second chance if you screw up once.

I take lots of caution while working on this and it's why I asked here. And this is the pics of my NST:
The large bushings towards the top of the NST (on the sides) are the high voltage outputs. The bolt that looks like it's connected directly to the case is center ground (this is what you'll want to connect the middle prong of your safety gap to), and the connections at the bottom of the one side are the mains connections.
 

atferrari

Joined Jan 6, 2004
4,771
Respectable contributors that actually know how to deal with those scaring transformers: how did YOU learn? o_OAsking, watching or divine inspiration?

I would be here asking as he did.
 

Thread Starter

steven2410

Joined Jul 7, 2014
16
In some cases, yes, but when it comes to Tesla coils you really MUST know what you are doing. You may not get a second chance if you screw up once.



The large bushings towards the top of the NST (on the sides) are the high voltage outputs. The bolt that looks like it's connected directly to the case is center ground (this is what you'll want to connect the middle prong of your safety gap to), and the connections at the bottom of the one side are the mains connections.
Thanks. That's what i though too. Have a good day!
 

DerStrom8

Joined Feb 20, 2011
2,390
Respectable contributors that actually know how to deal with those scaring transformers: how did YOU learn? o_OAsking, watching or divine inspiration?

I would be here asking as he did.
Much of your learning must be by the book at first. And even after you've gained a firm understanding of the circuits, the dangers, and so on you must practice extreme caution when building. As I said before, it's always a good idea to have someone nearby who knows CPR, or even better, someone who has built a Tesla coil before AND knows CPR.
 

atferrari

Joined Jan 6, 2004
4,771
Much of your learning must be by the book at first. And even after you've gained a firm understanding of the circuits, the dangers, and so on you must practice extreme caution when building. As I said before, it's always a good idea to have someone nearby who knows CPR, or even better, someone who has built a Tesla coil before AND knows CPR.
I understand Matt; with that high voltages and lasers there is no second chance, I know.

I did not want to sound sarcastic. Sorry if it was construed as such.
 

Thread Starter

steven2410

Joined Jul 7, 2014
16
Somehow, my NST does not work! I hook up its inputs to wall plug and the output to 2 conductor strips that are 2 cm apart. Apparently, nothing happens ( I was expected to see a spark between the gap). Does anyone know what might go wrong with it?
 

DerStrom8

Joined Feb 20, 2011
2,390
2 cm may be a bit too far for 9kV to jump. A simple rule of thumb is that it takes roughly 11kV to jump one centimeter (1.1kV/mm). Bring the conductor strips closer together (maybe half a centimeter) and give it another shot.

If you hear the transformer hum slightly, it should be working (unless the secondary is damaged).
 

Thread Starter

steven2410

Joined Jul 7, 2014
16
:( Look like i broke it by removing part of the GFI circuit ... There's nothing happen when power on ( not an even noise from it) ... Look like i'll need a new one !!!
 
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