Hi,

I know your neck hairs are STRAIGHT UP at this point. Why does this dude want to run about 10W at 110V (240V) ........ straight through a neon lamp BALLAST and through the neon lamp electrodes? This seemingly deserves holidays either on Rikers Island or might even qualify for Guantanamo! It's a bad, bad, bad idea; and one shouldn't even THINK about it. It's inherently heretic.

Here the basic idea:
I steal the "starter" from on old fashioned neon lamp; and replace it with an (empty) "dummy" (adaptor - to gain access to the power). Provided the neon lamp (tube) is powered (but obviously NOT started as it lacks the starter) that would enable me to access 110V (240V here in good old Europe) straight from the "dummy starter" (which is empty and doesn't function as starter). Right? Note that in my example the neon tube REMAINS IN THE FIXTURE! It just doesn't start; as there ain't no starter.

Then I could use that power (siphoned off the starter dummy) to hook up a transformer, get 12V output, run a 3 to 5W LED lamp.

Problem: With some "loss" of the transformer I would now run about 5 to 7-ish (gut feeling) Watt THROUGH the transformer AND through both electrodes. The neon lamp would likely NOT start (and it SHOULDN'T) the ballast should be fine with it; but the electrodes? Together they share a load of some less then 10 Watt (each less then 4 W presumably) - does that bother them? While a neon lamp is running: the electrodes anyway get quite some Watts run through them, so they should be used to it ......

By now you might be deeply concerned about my mental health; and would like to point out:
"DUDE! Why not simply accessing the power BEFORE it enters electrodes, ballasts, etc.?"

Or you might point out that I could simply use a "Plug & Play" ("Linear LED Direct Fit") LED tube.

But my requirement would be to have the old neon tube still in place; a dummy starter (rather: "starter adaptor") replacing the real starter; and then building a setup where either the real starter is in line (traditionally starting the remaining traditional neon tube) OR using the power to run a transformer for an about 5W of LED strip. All WITHOUT needing to access electric wiring - or replacing the neon tube (think: "75 year old grandpa from Idaho" should be able to handle it WITHOUT calling an electrician).

The main question I guess is:

A) would the fluorescent neon bulb mind being exposed to the 110/240 voltage WITHOUT starting (which it can't if the dummy starter uses the power for the transformer)? Potentially for DAYS on end!

B) Do the electrodes of the neon tube mind having 10W (5W each?) going through them for prolonged times (without the tube being started)?

C) Does the ballast mind? (Seemingly not as there are Plug&Play LED tubes).

D) And last not least: do I need any "special" 110V/12V (240V/12V) transformer (or some "add on") as it gets its power THROUGH the ballast? Again: I need only about 5W to 7W output from the transformer.

Thanks so much for considering my request for input.

Alexander from Riga

 

First, I'm not an expert on ballasts. The issue I'm seeing is that the neon bulbs (AKA Fluorescent Tubes) do not conduct electricity unless they're lit. They operate on high voltage. The starter merely supplies momentary power to each (or in some cases a single) end of the tube to heat and vaporize mercury within the tube to create an electrical path for the high voltage to follow from one end to the other of the tube.

I suspect the ballast will merely act like a choke in the proposed circuit. But I can only guess as you've not provided a schematic. I AM questioning why you wish to do such a thing and questioning whether it will work at all. Messing with ballasts presents a potential danger as high voltage may be present on the fluorescent supply lines, which you may wish to avoid at all costs. Those costs CAN include your life.

Without knowing more about your intended goal and your perceived method of reaching it - all I can say is "Please don't try that at home. Or anywhere else."

 

In a normal tube circuit the heaters at the tube ends carry significant current until the starter opens. Once the tube strikes, the voltage across the tube drops, as does the heater current. In the system you are proposing, the heater current would not drop. As the heaters aren't intended to carry high current for long I suspect they would quickly burn out, so there would be no power to run a transformer.

 

Hello,
Are you sure it is a neon lamp?
The neon lamp are usualy ver low power:
https://en.wikipedia.org/wiki/Neon_lamp
The fluorescent lamp uses a balast:
https://en.wikipedia.org/wiki/Fluorescent_lamp
There are electronic balasts for the fluorescent lamp available that uses extra connections for heating.
An other lamp that needs a balast is the SON lamp:
https://en.wikipedia.org/wiki/Sodium-vapor_lamp

Bertus

 

In a normal tube circuit the heaters at the tube ends carry significant current until the starter opens. Once the tube strikes, the voltage across the tube drops, as does the heater current. In the system you are proposing, the heater current would not drop. As the heaters aren't intended to carry high current for long I suspect they would quickly burn out, so there would be no power to run a transformer.

Well, the question is: would about 8 Watt (split into 4 Watt each side) pose "harm" to the heaters? Maybe I have to simply try it out

 

Hi,

I dont think running the heaters for long periods of time is a good idea as they were meant to run only for a few seconds. Also big waste of power.

Whenever we do new stuff with old stuff there's always a test phase where we have to test it carefully to make sure nothing can go wrong. Usually it is best to stick with the old methods but you could also look at newer methods that have already been established. For these tubes the old method of using the heater has been replaced with using a high voltage spike to start the lamp. You could look into that.

Before the lamp starts however i dont think there is any current flow though the lamp itself, just the heaters, unless you use the high voltage spike and then it starts quickly so current will flow very soon.

 

What's the purpose? What's the goal?

 

think: "75 year old grandpa from Idaho" should be able to handle it WITHOUT calling an electrician

.... is the goal. But Grandpa is still going to have to stand on a rickety chair to unplug the starter and plug in the adapter. If he does remember to switch off at the mains before doing that he'll avoid electrocution, but his sense of balance isn't what it used to be, so there are safety issues here .

 

Hello,

You might want to have a look at the following page for the fuction of the starter in a fluorescent tube circuit:
https://home.howstuffworks.com/fluorescent-lamp4.htm

Bertus

 

.... is the goal. But Grandpa is still going to have to stand on a rickety chair to unplug the starter and plug in the adapter. If he does remember to switch off at the mains before doing that he'll avoid electrocution, but his sense of balance isn't what it used to be, so there are safety issues here .

Ohh, nooo: Here goes grandpa!

But wait: He ain't stupid and reads the install manual that INSTRUCTS him to switch off mains! And the neon lights are in the kitchen, under the cabinets, easy to reach! But to avoid all risks: Grandma has the garden water hose in her hands - ready to hose him down to wash off those darn electrons should they befall him! I think they are safe!

 

Hello,

You might want to have a look at the following page for the fuction of the starter in a fluorescent tube circuit:
https://home.howstuffworks.com/fluorescent-lamp4.htm

Bertus

I think I am aware of the function.

 

What's the purpose? What's the goal?

Without giving too much away:

A large percentage of Americans have neon lights in their homes. Imagine that (for whatever reason) such a person wanted to run a LED-light WITHIN the neon lamp housing! WITHOUT losing the ability to run the neon-light! WITHOUT having to call an electrician. WITHOUT changing the "tube". The way I am investigating: accessing 110V where it is readily available: at the STARTER! Prime problem: Whatever current you draw: it goes THROUGH the heaters! So the main question is:
How many Watts of continued current (or "load") will a starter take WITHOUT deterring (burning through, evaporating material, etc).

And yeah: Obviously the person should simply exchange the neo-tube for a "plug&play" LED tube, OR access power where it arrives: at the power line when it enters the neon-lamp! I get that.

 

Hi,

I dont think running the heaters for long periods of time is a good idea as they were meant to run only for a few seconds. Also big waste of power.

...........

GOOD POINT: I should measure the RESISTANCE of a heater ....

I did quickly - it seemed to be around 4 Ohm - but also it seems to fluctuate. Initially it seems very high, and goes down. Have only quickly held a tester on a tube......

I want to see what happens if I run 4W at 110V (here: 240V) through one heater for a while? Problem might be that a transformer (needed to power the LED) might have some "empty load" all the time?

Maybe I should give up on the idea accessing 10W of power through the 2 heaters altogether.

 

So - without giving too much away, you want a night light inside the fluorescent fixture. I realize you keep calling it "Neon" but honestly, it's not Neon but rather fluorescent. Semantics not withstanding, you want a night light that's either always on and drawing very little current. At least that's what I'm picking up here. Correct me if I'm wrong - but if the light is controlled from a wall switch then when the switch is off then no power is present at the fixture to run either the light or the night-light. Further, how do you light the fluorescent light if the starter has been modified?

If you want a night light inside the fixture, and I've seen such before, mostly in the form of emergency lighting; the idea of having a night light that is on when the light is off means you're going to need a different source of power. One that is on when the light is off OR one that is on at all times from an uninterrupted source.

If it's night lights you want - they have electrical cover plates with built in night lights. See This:

 

GOOD POINT: I should measure the RESISTANCE of a heater ....

I did quickly - it seemed to be around 4 Ohm - but also it seems to fluctuate. Initially it seems very high, and goes down. Have only quickly held a tester on a tube......

I want to see what happens if I run 4W at 110V (here: 240V) through one heater for a while? Problem might be that a transformer (needed to power the LED) might have some "empty load" all the time?

Maybe I should give up on the idea accessing 10W of power through the 2 heaters altogether.

Hello again,

Not sure if you are aware of this or not but, when you measure the resistance of a light bulb or heater you may see a wide variation in resistance depending on how much voltage you apply. That is because of the way the resistance varies as the filament heats up.
Ratios cold to hot could be as high as 1 to 10 (so if 10 Ohms cold then 100 Ohms hot).

 

OK, I haven't looked at the wiring, but...
Each end contains a resistive element that can emit electrons at each end.
The ballast is basically a lossless inductor that functions as a current regulator.
There is some mercury in the tube.
While starting, you connect these resistive elements in series and spit out some electrons. It's enough to partially ionize the gas.
The starter releases and the mercury vapor excites the phosphorous and emits the light color of choice.

There are no starters on rapid-start lamps.

The current waveform is likely wierd. I did do some real-time intensity measurements on a UV lamp that used a neon light transformer.
The intensity output looked a lot like a whale shape.

 

Hello,

You might want to have a look at this page:
http://www.repairfaq.org/sam/flamp.htm

Bertus

 

Presently the vasy majority of florescent lights do not use a starter. The starter is used to allow some current to flow and heat the filaments at each end so that when it opens the inductive spike will ionize the gas and start the tube glowing. So the first flaw in the theory is presuming the presence of a starter and the second flaw is presuming that there is enough current available to be worth the effort. The ballast serves to limit the current when the lamp starts conducting. But none of the florescent lamp fixtures used in the USA for the past 30 years utilize a starter. Presently a more complex ballast provides heater current and then a high voltage to get things going, at which point it limits the current to the desired power level.
And the electronic ballasts do it by some other form of magic yet.
The solution is removing the ballast and providing direct mains connection for internally regulated LED assemblies. The proposed concept is about 45 years out of date. The cheaper LED tubes sell for well below $10 locally here.

 

Hi,

Another point is that the current though the tube has to be AC with no DC component. That is to prevent migration of the 'cathode' material which is what i think causes one end of the tube to darken. The modern battery operated electronic circuits therefore have a capacitor in series with the converter output.

 

Hello,

You might want to have a look at this page:
http://www.repairfaq.org/sam/flamp.htm

Bertus

Presently the vasy majority of florescent lights do not use a starter. The starter is used to allow some current to flow and heat the filaments at each end so that when it opens the inductive spike will ionize the gas and start the tube glowing. So the first flaw in the theory is presuming the presence of a starter and the second flaw is presuming that there is enough current available to be worth the effort. The ballast serves to limit the current when the lamp starts conducting. But none of the florescent lamp fixtures used in the USA for the past 30 years utilize a starter. Presently a more complex ballast provides heater current and then a high voltage to get things going, at which point it limits the current to the desired power level.
And the electronic ballasts do it by some other form of magic yet.
The solution is removing the ballast and providing direct mains connection for internally regulated LED assemblies. The proposed concept is about 45 years out of date. The cheaper LED tubes sell for well below $10 locally here.

Thanks. LED tubes sell for as low as US $5 here by now. The only reason I wanted to access power through the starter was to AVOID forcing people to call a certified electrician.

But the entire idea seems not working for many reasons.

Question: The "Plug & Play" LED tubes that come with a shortcuted starter dummy (if the fixture uses a starter); do they work WITHOUT having to bypass the ballast with the average U.S. fixture? Those that do use a starter: seems Plug&Play LED's work if the starter is replaced by the shortcuted dummy. But those which have a ballast unit that starts the fluorescent tube directly with high voltage?