I have new neon sign with a bad transformer (has a short and works sporadically), it is a 5kv 15MA transformer. I bought a new one that is 5kv 30ma and the neon fades towards the end of the run. It is nice and bright the whole run with the original transformer so I am assuming the 30ma vs 15ma is a problem.

Any advice, im having a hard time finding a 5kv 15ma replacement.

On 2020/07/24 9:27 a.m., Brian Struckmeier wrote:
I have new neon sign with a bad transformer (has a short and works sporadically), it is a 5kv 15MA transformer. I bought a new one that is 5kv 30ma and the neon fades towards the end of the run. It is nice and bright the whole run with the original transformer so I am assuming the 30ma vs 15ma is a problem.

Any advice, im having a hard time finding a 5kv 15ma replacement.


30ma is more available power, so it is better - the transformer will
handle a larger load. Your transformer may not be putting out 5KV though...

This is where an AC/DC HV probe is handy. You can get 10:1 on eBay and
other sources. Look for ones that appear to be well insulated! If it
comes from China don't stand on a cement floor when using it!


John :-#)#

Brian Struckmeier wrote:

I have new neon sign with a bad transformer (has a short and works
sporadically), it is a 5kv 15MA transformer. I bought a new one that is
5kv 30ma and the neon fades towards the end of the run. It is nice and
bright the whole run with the original transformer so I am assuming the
30ma vs 15ma is a problem.

Any advice, im having a hard time finding a 5kv 15ma replacement.

The extra current may be damaging the electrodes and causing out-gassing
or overheating the tube so the neon pressure rises. Is there a
possibility that there is an adjustable magnetic shunt inside the
transformer that could be adjusted to reduce the current?

Please be careful - with those sorts of currents and voltages, your
first mistake could well be your last.


--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On 2020/07/24 10:36 a.m., Adrian Tuddenham wrote:
Brian Struckmeier wrote:

I have new neon sign with a bad transformer (has a short and works
sporadically), it is a 5kv 15MA transformer. I bought a new one that is
5kv 30ma and the neon fades towards the end of the run. It is nice and
bright the whole run with the original transformer so I am assuming the
30ma vs 15ma is a problem.

Any advice, im having a hard time finding a 5kv 15ma replacement.

The extra current may be damaging the electrodes and causing out-gassing
or overheating the tube so the neon pressure rises. Is there a
possibility that there is an adjustable magnetic shunt inside the
transformer that could be adjusted to reduce the current?

Please be careful - with those sorts of currents and voltages, your
first mistake could well be your last.



Interesting, I did not realize that Neon transformers were current
limiting, behaving somewhat like a ballast on fluorescent lamps:

https://www.richieburnett.co.uk/ballast.html

--------------(quote)---------------------------------------

Neon sign transformers have built-in magnetic shunts which give current
limiting. In its intended use as a supply for neon tube, the high open
circuit voltage of the transformer is used to strike an arc in the neon
tube. Once an arc has formed inside the neon tube, the current must be
limited to prevent overheating of the neon tube and the transformer due
to excessive current flow. (The hotter the arc gets, the more current
flows, so it gets hotter etc€¦)

----------------(end quote)----------------------------------

Thanks for the info! Live and learn, eh?

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

In article ,
says...

Interesting, I did not realize that Neon transformers were current
limiting, behaving somewhat like a ballast on fluorescent lamps:

https://www.richieburnett.co.uk/ballast.html

--------------(quote)---------------------------------------

Neon sign transformers have built-in magnetic shunts which give current
limiting. In its intended use as a supply for neon tube, the high open
circuit voltage of the transformer is used to strike an arc in the neon
tube. Once an arc has formed inside the neon tube, the current must be
limited to prevent overheating of the neon tube and the transformer due
to excessive current flow. (The hotter the arc gets, the more current
flows, so it gets hotter etc?)

----------------(end quote)----------------------------------

Thanks for the info! Live and learn, eh?

John :-#)#

Exactly like a grown-up version of your tiny neon pilot lamp in an AC
power socket with its ballast resistor...

Mike.

On 2020-07-24 14:20, John Robertson wrote:
On 2020/07/24 10:36 a.m., Adrian Tuddenham wrote:
Brian Struckmeier wrote:

I have new neon sign with a bad transformer (has a short and works
sporadically), it is a 5kv 15MA transformer.Â*Â* I bought a new one
that is
5kv 30ma and the neon fades towards the end of the run.Â* It is nice and
bright the whole run with the original transformer so I am assuming the
30ma vs 15ma is a problem.

Any advice, im having a hard time finding a 5kv 15ma replacement.

The extra current may be damaging the electrodes and causing out-gassing
or overheating the tube so the neon pressure rises.Â* Is there a
possibility that there is an adjustable magnetic shunt inside the
transformer that could be adjusted to reduce the current?

Please be careful - with those sorts of currents and voltages, your
first mistake could well be your last.



Interesting, I did not realize that Neon transformers were current
limiting, behaving somewhat like a ballast on fluorescent lamps:

https://www.richieburnett.co.uk/ballast.html

--------------(quote)---------------------------------------

Neon sign transformers have built-in magnetic shunts which give current
limiting. In its intended use as a supply for neon tube, the high open
circuit voltage of the transformer is used to strike an arc in the neon
tube. Once an arc has formed inside the neon tube, the current must be
limited to prevent overheating of the neon tube and the transformer due
to excessive current flow. (The hotter the arc gets, the more current
flows, so it gets hotter etc€¦)

----------------(end quote)----------------------------------

Thanks for the info! Live and learn, eh?

John :-#)#


HeNe laser supplies are the same way. You have to match them to the tube.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

On 2020/07/24 11:29 a.m., Mike Coon wrote:
In article ,
says...

Interesting, I did not realize that Neon transformers were current
limiting, behaving somewhat like a ballast on fluorescent lamps:

https://www.richieburnett.co.uk/ballast.html

--------------(quote)---------------------------------------

Neon sign transformers have built-in magnetic shunts which give current
limiting. In its intended use as a supply for neon tube, the high open
circuit voltage of the transformer is used to strike an arc in the neon
tube. Once an arc has formed inside the neon tube, the current must be
limited to prevent overheating of the neon tube and the transformer due
to excessive current flow. (The hotter the arc gets, the more current
flows, so it gets hotter etc?)

----------------(end quote)----------------------------------

Thanks for the info! Live and learn, eh?

John :-#)#

Exactly like a grown-up version of your tiny neon pilot lamp in an AC
power socket with its ballast resistor...

Mike.


I have a Neon Christmas tree (glass tube outline) that was made for my
grandfather by his employees (E.L. Ruddy in Toronto) during the
depression (as Granny told me years ago). Stands about 14 inches tall
and is still working just fine. Haul it out every winter and plug it
into its base.

I can post a picture if anyone is interested...

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."

On Friday, July 24, 2020 at 6:10:37 PM UTC-4, John Robertson wrote:
On 2020/07/24 11:29 a.m., Mike Coon wrote:
In article ,
says...

Interesting, I did not realize that Neon transformers were current
limiting, behaving somewhat like a ballast on fluorescent lamps:

https://www.richieburnett.co.uk/ballast.html

--------------(quote)---------------------------------------

Neon sign transformers have built-in magnetic shunts which give current
limiting. In its intended use as a supply for neon tube, the high open
circuit voltage of the transformer is used to strike an arc in the neon
tube. Once an arc has formed inside the neon tube, the current must be
limited to prevent overheating of the neon tube and the transformer due
to excessive current flow. (The hotter the arc gets, the more current
flows, so it gets hotter etc?)

----------------(end quote)----------------------------------

Thanks for the info! Live and learn, eh?

John :-#)#

Exactly like a grown-up version of your tiny neon pilot lamp in an AC
power socket with its ballast resistor...

Mike.


I have a Neon Christmas tree (glass tube outline) that was made for my
grandfather by his employees (E.L. Ruddy in Toronto) during the
depression (as Granny told me years ago). Stands about 14 inches tall
and is still working just fine. Haul it out every winter and plug it
into its base.

I can post a picture if anyone is interested...

John :-#)#


I certainly wouldn't mind seeing it John.

On 2020/07/24 6:53 p.m., John-Del wrote:
On Friday, July 24, 2020 at 6:10:37 PM UTC-4, John Robertson wrote:
On 2020/07/24 11:29 a.m., Mike Coon wrote:
In article ,
says...

Interesting, I did not realize that Neon transformers were current
limiting, behaving somewhat like a ballast on fluorescent lamps:

https://www.richieburnett.co.uk/ballast.html

--------------(quote)---------------------------------------

Neon sign transformers have built-in magnetic shunts which give current
limiting. In its intended use as a supply for neon tube, the high open
circuit voltage of the transformer is used to strike an arc in the neon
tube. Once an arc has formed inside the neon tube, the current must be
limited to prevent overheating of the neon tube and the transformer due
to excessive current flow. (The hotter the arc gets, the more current
flows, so it gets hotter etc?)

----------------(end quote)----------------------------------

Thanks for the info! Live and learn, eh?

John :-#)#

Exactly like a grown-up version of your tiny neon pilot lamp in an AC
power socket with its ballast resistor...

Mike.


I have a Neon Christmas tree (glass tube outline) that was made for my
grandfather by his employees (E.L. Ruddy in Toronto) during the
depression (as Granny told me years ago). Stands about 14 inches tall
and is still working just fine. Haul it out every winter and plug it
into its base.

I can post a picture if anyone is interested...

John :-#)#


I certainly wouldn't mind seeing it John.


https://flippers.com/images/XmasNeonSmokey.JPG

https://flippers.com/images/XmasNeonTree.JPG

Old photos, that don't show the metal base. All I have at the moment. It
is sitting on a 1929ish RCA radio, sitting on a 1920s radio speaker
cabinet. Photos taken almost twenty years ago.

John :-#)#

In article ,
says...

I have a Neon Christmas tree (glass tube outline) that was made for
my
grandfather by his employees (E.L. Ruddy in Toronto) during the
depression (as Granny told me years ago). Stands about 14 inches tall
and is still working just fine. Haul it out every winter and plug it
into its base.

I can post a picture if anyone is interested...

John :-#)#


I certainly wouldn't mind seeing it John.


https://flippers.com/images/XmasNeonSmokey.JPG

https://flippers.com/images/XmasNeonTree.JPG

Old photos, that don't show the metal base. All I have at the moment.
It is sitting on a 1929ish RCA radio, sitting on a 1920s radio speaker
cabinet. Photos taken almost twenty years ago.

John :-#)#

How refreshing that the shape has an smidgen of randomness!

Mike.

On 7/25/2020 7:34 AM, Mike Coon wrote:
How refreshing that the shape has an smidgen of randomness!

Mike.


My thoughts exactly.

'Twere mine, I would put it up every year too. To remember grandpa and
because it's cool.

On 2020/07/25 5:04 a.m., Bob Engelhardt wrote:
On 7/25/2020 7:34 AM, Mike Coon wrote:
How refreshing that the shape has an smidgen of randomness!

Mike.


My thoughts exactly.

'Twere mine, I would put it up every year too.Â* To remember grandpa and
because it's cool.


Exactly. It goes up every year for a month or so...

Thanks,

John :-#)#

Nice. Did you ever consider building a lexan box to mount it in?

On 2020/07/25 11:00 a.m., John-Del wrote:

Nice. Did you ever consider building a lexan box to mount it in?


No, my family are careful around it and we no longer have a cat...

I agree it would be very unfortunate if it ever broke.

John :-#)#

Brian Struckmeier wrote:
I have new neon sign with a bad transformer (has a short and works sporadically), it is a 5kv 15MA transformer. I bought a new one that is 5kv 30ma and the neon fades towards the end of the run. It is nice and bright the whole run with the original transformer so I am assuming the 30ma vs 15ma is a problem.

Any advice, im having a hard time finding a 5kv 15ma replacement.

Well you're overloading the neon tube and may cause damage to it.

I found some 4kV 15ma electronic power supplies online. Might work fine.

On 7/25/20 6:52 PM, Cydrome Leader wrote:
Brian Struckmeier wrote:
I have new neon sign with a bad transformer (has a short and works sporadically), it is a 5kv 15MA transformer. I bought a new one that is 5kv 30ma and the neon fades towards the end of the run. It is nice and bright the whole run with the original transformer so I am assuming the 30ma vs 15ma is a problem.

Any advice, im having a hard time finding a 5kv 15ma replacement.

Well you're overloading the neon tube and may cause damage to it.

I found some 4kV 15ma electronic power supplies online. Might work fine.



As a test, you could put a 330K resistor in series with the neon tube.
That will limit the current to 15 mA.

However, the power rating needs to be in excess of 75 watts.

--
"I am a river to my people."
Jeff-1.0
WA6FWi
http:foxsmercantile.com

As well as the constant high voltage.

John Robertson wrote:

On 2020/07/25 11:00 a.m., John-Del wrote:

Nice. Did you ever consider building a lexan box to mount it in?


No, my family are careful around it and we no longer have a cat...

Did it rub against the transformer?

--
~ Adrian Tuddenham ~
(Remove the ".invalid"s and add ".co.uk" to reply)
www.poppyrecords.co.uk

On 2020/07/26 2:17 a.m., Adrian Tuddenham wrote:
John Robertson wrote:

On 2020/07/25 11:00 a.m., John-Del wrote:

Nice. Did you ever consider building a lexan box to mount it in?


No, my family are careful around it and we no longer have a cat...

Did it rub against the transformer?


The photo doesn't show the chrome metal box that the transformer is
mounted in. The HV outputs are in two chrome metal tubes that the tree
plugs into...

John :-#)#

--
(Please post followups or tech inquiries to the USENET newsgroup)
John's Jukes Ltd.
MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3
(604)872-5757 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."