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Need help replacing neon sign transformer

sideburn

New Member
Hey all,

I don't know much about how neon signs work, and I dopant want to over volt it or burn it up somehow so I was hoping someone can confirm with me that a transformer I found will work.

The one that came with the sign and is faulty (keeps cutting on and off) shows that it is and EverBrite:

Input - 120v 60hz 115W.
Output - 4.5-0-4.5kv 30ma

The one I found on amazon has the following specs:

Input: 100-240 VAC 50/60Hz 5-25W
Output: 3kV 30mA;

When the sign was working, I measured the voltage by connecting a high voltage prop to the wires on the sign and was reading what appeared to be 2,200kv.

I have a pretty good grasp on electronics but my first thought is the only way to burn out a neon sign would be to give it too many KV right?
I read something about tit being about the current though... ? ...

So I assume this new (cheap chinese) transformer will work ok?

Thanks for any info,

-Tavis
 
Last edited:

Boudica

Back to "educational purposes"
Hey all,

I don't know much about how neon signs work, and I dopant want to over volt it or burn it up somehow so I was hoping someone can confirm with me that a transformer I found will work.

The one that came with the sign and is faulty (keeps button on and off) shows that it is and EverBrite:

Input - 120v 60hz 115W.
Output - 4.5-0-4.5kv 30ma

The one I found on amazon has the following specs:

Input: 100-240 VAC 50/60Hz 5-25W
Output: 3kV 30mA;

When the sign was working, I measured the voltage by connecting a high voltage prop to the wires on the sign and was reading what appeared to be 2,200kv.

I have a pretty good grasp on electronics but my first thought is the only way to burn out a neon sign would be to give it too many KV right?
I read something about tit being about the current though... ? ...

So I assume this new (cheap chinese) transformer will work ok?

Thanks for any info,

-Tavis
Don't you need a license to work on electric signs?
 

sideburn

New Member
Don't you need a license to work on electric signs?
No it is a vintage OPEN sign I bought off of a private party and its going in my workshop at home... it was working ok but it is intermittently cutting off and on... he said it has issues and probably needs a new transformer.
 

Todd Jelle

New Member
You actually should measure the total tube length then add 1 ft per pair set of electrodes. Use a neon chart to see if your transformer is within range for your total footage of tube.
or....vintex & other mfg make transformers that self adjust for the load, but many also have a limit to the load range. I think the transformer you show would likely do the job (if it is the original trans). As a rule you are better to under load the trans as opposed to over loading it. If someone else bought a transformer to replace the original & it is to small , that could cause the issues your having. Again.... best to calculate to neon load to be safe.

Neon load chart
 

sideburn

New Member
You actually should measure the total tube length then add 1 ft per pair set of electrodes. Use a neon chart to see if your transformer is within range for your total footage of tube.
or....vintex & other mfg make transformers that self adjust for the load, but many also have a limit to the load range. I think the transformer you show would likely do the job (if it is the original trans). As a rule you are better to under load the trans as opposed to over loading it. If someone else bought a transformer to replace the original & it is to small , that could cause the issues your having. Again.... best to calculate to neon load to be safe.

Neon load chart
I Know the one that’s on there now is the original. And it says 4.5kv I think ? Not sure what the -0- means in “4.5-0-4.5kv”. But when the sign was on and working I measured 2.2kv off the wires connected to the tube. It’s a single run tube with one transformer.

The new one that will be arriving tomorrow claims 3kv. But it’s cheap:

HB-C02TE 3KV Power Supply for Glass Neon Sign Light Electronic Neon Signs Lights Transformer with Black Plug https://a.co/d/f8t9lrh
 

sideburn

New Member
Well like I mentioned, I measured 2.2kv with the sign lit so I’m hoping 3kv will work. I’ll have to see. It should arrive today…
 

netsol

Active Member
Hey all,

I don't know much about how neon signs work, and I dopant want to over volt it or burn it up somehow so I was hoping someone can confirm with me that a transformer I found will work.

The one that came with the sign and is faulty (keeps cutting on and off) shows that it is and EverBrite:

Input - 120v 60hz 115W.
Output - 4.5-0-4.5kv 30ma

The one I found on amazon has the following specs:

Input: 100-240 VAC 50/60Hz 5-25W
Output: 3kV 30mA;

When the sign was working, I measured the voltage by connecting a high voltage prop to the wires on the sign and was reading what appeared to be 2,200kv.

I have a pretty good grasp on electronics but my first thought is the only way to burn out a neon sign would be to give it too many KV right?
I read something about tit being about the current though... ? ...

So I assume this new (cheap chinese) transformer will work ok?

Thanks for any info,

-Tavis
If I am reading your specs correctly, the first item is producing much higher voltage but is CENTER TAPPED

it does not appear to be a good replacement to me
 

Ginnyhoang1308

New Member
If you're using traditional neon tube sign, I recommend that you may try this led neon sign like the product on this website pageneon.com

It will be much easier to install and fix. And much cheaper I think.
 

ProSignTN

New Member
As a 30 yr vet, I've never hear the term Center Tapped. There are two ways to wire a neon tube. Every hanging window sign, or beer sign, etc. I've ever seen has been wired with no ground. The transformer leads are attached to each end of the tubing. GTO cable (rated at 15kv) is used and each piece of tubing is also connected with GTO cable. So, a complete circuit. Each end of a traditional coil and core transformer will produce half of what the transformer is listed as (15kv - 7.5 kv each lead, 10kv - 5kv each lead). This is the preferred method as it allows the current to flow through the neon from a shorter length than the other method. The other method, known as Mid Point Ground, is used for applications such as strip lighting on a building front. For MPG you set the transformer in the center of the tubing and wire each half to one lead of the transformer, while grounding the end farthest from the transformer. This method saves the energy required to 'push' power through the GTO for long returns.
 

Medina Signs

Old Member
Like was earlier posted - Buy a self adjusting (indoor) xformer - Sleeveless GTO #16 awg, 15kV and 36” long. Ground fault and open circuit protection. Overload detection. Indoor High Light Output, Self-Adjusting Voltage.

SS1235ICH ALLANSON PLASTI-PAK INDOOR​

Available at N Glantz
 

bongomundo

New Member
I also could use some advice on replacing an old transformer. The tube size is 10mm and the glass is about 7.5ft in length on the visible side of the sign, so not including the connectors. It is a red neon light.
The original transformer is a 7500/18mA.
The one chart I looked at said I could use about a 5000/30.
Can I replace this big block in the picture with one of these small $20-30 transformers I see on Ebay?
 

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netsol

Active Member
As a 30 yr vet, I've never hear the term Center Tapped. There are two ways to wire a neon tube. Every hanging window sign, or beer sign, etc. I've ever seen has been wired with no ground. The transformer leads are attached to each end of the tubing. GTO cable (rated at 15kv) is used and each piece of tubing is also connected with GTO cable. So, a complete circuit. Each end of a traditional coil and core transformer will produce half of what the transformer is listed as (15kv - 7.5 kv each lead, 10kv - 5kv each lead). This is the preferred method as it allows the current to flow through the neon from a shorter length than the other method. The other method, known as Mid Point Ground, is used for applications such as strip lighting on a building front. For MPG you set the transformer in the center of the tubing and wire each half to one lead of the transformer, while grounding the end farthest from the transformer. This method saves the energy required to 'push' power through the GTO for long returns
 

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netsol

Active Member
a very common type of circuit, just not for your industry. just because it is "center tapped" doesn't mean you have to use the tap.
just insulate it and use like a regular transformer
 

bongomundo

New Member
BTW, First Post Newbie, The light came out of a 1930s cafe so it may be older than you guys, lol. I am just trying to get it to work for fun and this is my first look at the innards of a neon sign.
I did not understand the label on the transformer. The picture is what the tube connecter looks like inside the housing.
I see some $200 transformers online but also see some very inexpensive transformers for sale and am trying to figure out if I can get away with the cheaper ones.
The transformer is located midway between the connecters.
 

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Gettin'By

New Member
If they are significantly cheaper I'd start to think about applying the "you get what you pay for" principle. I'm real leery of that with electricity. Something's making it cheap. Cheap materials, cheap manufacturing, or lack of any kind of quality control. Maybe all of that and more. Not saying they won't work, but do some research on them and read reviews. Maybe tell the folks what brand and see if anyone knows anything.
 

Gino

Premium Subscriber
No it is a vintage OPEN sign I bought off of a private party and its going in my workshop at home... it was working ok but it is intermittently cutting off and on... he said it has issues and probably needs a new transformer.

As long as this is going in your home, play around with it, til ya zap yourself or someone in your family, but when working as a professional out in the field, LEARN FROM THIS GUY. don't f*ck around with stuff you don't know anything about. Get a professional to do it.
 
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