USB powered Neon Indicator lamps?

[Fungus]

you can certainly connect NE-2s in series.....

Which is power rating of those tiny NE-2s?

They have a "striking voltage" of about 90V to turn them on.

But once they're lit up they need 50-60V at about 0.5mA, depending on the manufacturer (some are 0.3mA, some are 0.7mA...)

55V x 0.0005mA gives 0.0275W

[Fungus]

Yes, you can certainly connect NE-2s in series.....

I was more worried about connecting several strings in parallel. If one string lights up first would it prevent the other strings from striking? I guess I'll find out in the next few days.

[BravoV]

You can even light them up wirelessly with the right oscillator and antenna....

How ? Is it easy to build ?

Intermezzo ... inspired by uBeam wireless charging , a wireless powered flashlight maybe ? Maybe we should launch a KS campaign for it.  ....j/k

[eneuro]

I was more worried about connecting several strings in parallel. If one string lights up first would it prevent the other strings from striking?

My guess is all neon strings will start and share current in parallel, but didn't checked it yet, so let us know
When you will try add to live circuit new neons than probably they will now glow without turning everything off and than again on, while neons were some time ago used as some kind of voltage regulators.

I'd like to power up a few 1.5 meter long 55W rated flourescent lamps to create something like rays of sun (etc) and trying to figure out what could be better-connect them in parallel or in series to my a few kV low current (limited by resistors for the moment, but we can limit also fly back primary current and play with its resonant frequency) .

[eneuro]

You can even light them up wirelessly with the right oscillator and antenna....

... a wireless powered flashlight maybe ? ...

Actually I've made a few turns with wires around two connected rooms, so total loop length is 30 meters, while bigger room has dimensions 5 m x 4m, so total length around is ~20 meters smaller one ~ 10 meters, so average diameter will be ~9 m for bigger room and 3m for smaller one.
There are a few turns, so my plan is connect ZVS driver, than make many turns of smaller inductor and capacitor in parallel to match its resonant frequency and... add leds in antiparallel.
But after looking at those nice NE-2 neons, capable of working with AC voltages, maybe  It will be better, make somethign like many small Tesla coil's for each neon and power up plenty of them using this huge a few turns coil around room 
I'll post results there where sometime ago started WPT thread  eevblog:   Tesla (Tower) Wireless Power Transfer

Lets challenge this u  Beam and powerup house wireless without bloody stupid idea of harmfull for animals ultrasound 

[LaserSteve]

If you have the correct series resistor in in your string, all parallel neon strings will glow Provided:

You have about ~20VDC  more then the minimum striking point of the worse string.
You have a supply capable of enough current for all strings. 

So if your not "starving" the system with a minimalist approach or undersized power supply, all strings will light.

One of the ways you can tell if your current starved is: The cathode electrode is not uniformly covered in plasma or the plasma moves around the electrode in a small spot. 

Illuminate the neon lamps electrodes  with a  350 nm  UV LED and the strike time will go way down. The strike voltage will be a few volts lower due to free electrons provided by the photoelectric effect  :-)   If you have an electrometer you will see a small current from your neon "photodiode", provided you only illuminate one electrode. However the mean free path is small in the lamp due to a high gas pressure and the current will be tiny compared to a phototube.

The purple glow during destruction is residual nitrogen released from the electrodes and glass envelope when overheated, coupled with a tiny bit of the sputtered vapor from the electrode metal. 

As for inductive coupling, it was and is used for RF pumped  fluorescent lamps used when the lamp is in inaccessible place and needs a long life.   I used to have a full sized  pyrex glass coffee cup with hollow walls, filled with neon. (Plasma Mug)  You placed it on a inductive RF source pad with a high peak voltage field, and it lit. Was an Ebay item for a while, I don't know if they are still made.

Here is one cool induction coupled application of neon:

http://www.obsta.com/contents/balisor-for-high-voltage-lines/balisor-for-high-voltage-lines-2



Maybe I need to shoot a video of the five pound bag of neon lamps placed in the microwave oven for a few seconds. :-)

Steve

[Fungus]

One of the ways you can tell if your current starved is: The cathode electrode is not uniformly covered in plasma or the plasma moves around the electrode in a small spot. 

That's happening to me. Thanks for letting me know the reason.

I haven't really calculated the resistor value yet or anything like that, so I guess I'll need to tweak it.

Illuminate the neon lamps electrodes  with a  350 nm  UV LED and the strike time will go way down. The strike voltage will be a few volts lower due to free electrons provided by the photoelectric effect  :-)

 

Maybe I need to shoot a video of the five pound bag of neon lamps placed in the microwave oven for a few seconds. :-)