USB powered Neon Indicator lamps?

[sarepairman2]

finally a use for all the multicolored neon bulbs I bought on ebay

[Fungus]

Use the 12V input version. It maintains a higher output voltage (which is > 72V guaranteed over the full output power range)

On my 12V USB port...?

[Fungus]

finally a use for all the multicolored neon bulbs I bought on ebay

I got blue ones...

[Psi]

Use the 12V input version. It maintains a higher output voltage (which is > 72V guaranteed over the full output power range)

On my 12V USB port...?

oh right, for some reason i thought you were powering it from a computer and had the internal +5 and +12 available.

You can still do it, but output will be min of 84V  Should be fine.

[Fungus]

Use the 12V input version. It maintains a higher output voltage (which is > 72V guaranteed over the full output power range)

On my 12V USB port...?

oh right, for some reason i thought you were powering it from a computer and had the internal +5 and +12 available.

This option will be explored if the little eBay boards don't work out. I'm waiting for them to arrive...

[Psi]

Is it just me that has the urge to go get some pliers wherever seeing a row of little glass neons?

crunch,crunch,crunch.

[Fungus]

Is it just me that has the urge to go get some pliers wherever seeing a row of little glass neons?

Apprently not

Who knew?

[wagon]

Try dumping 5-10kV into a neon, WITHOUT a resistor.  Pretty purple glow instead of orange.  (I repair electric fence energisers, I love to see what their outputs can destroy!)

[SeanB]

Try dumping 5-10kV into a neon, WITHOUT a resistor.  Pretty purple glow instead of orange.  (I repair electric fence energisers, I love to see what their outputs can destroy!)

I tried to destroy an old Pentium using the fence energiser, passing the output through the die using a thin bare coper wire held by the pins on the one side and another on the other side pins. Around 30 zaps, and put it back in the old motherboard, and the bleeding thing posted and booted as if nothing was wrong.  Destroyed it finally by connecting to a 12V battery till the pins melted off, though I was thinking the silicon inside probably was still working.

[Fungus]

I tried to destroy an old Pentium using the fence energiser, passing the output through the die using a thin bare coper wire held by the pins on the one side and another on the other side pins. Around 30 zaps, and put it back in the old motherboard, and the bleeding thing posted and booted as if nothing was wrong. 

You probably connected to ground pins on both sides.

[SeanB]

I looked for rows where there were none with the placement of the wire, and tried with a supply pin as single input as well. Those are tough, they would only fail if you left the heatsink off and powered it up, and only the Celeron without a heat spreader on it. The canned ones would run partway through post then do an emergency thermal shutdown. Was expensive for the guy who left the plastic paste cover on the heatsink and clipped it on and turned it on. Needed new processor and motherboard as the plastic clip glued it into the socket before the bang.

[g0hjq]

There are some videos on my Youtube Channel showing various configurations of Neon.

https://youtu.be/hfjhknxc9ek
https://youtu.be/PimL80JjmG0
https://youtu.be/JSSBvxIcyls
https://youtu.be/f6Xg9GPGwBM

They only need a few milliamps at 90v DC. I used a simple MC34063 driving a step-up transformer, similar to the one in figure 27 in here: http://www.onsemi.com/pub_link/Collateral/AN920-D.PDF but with a different transformer turns ratio.

[Fungus]

There are some videos on my Youtube Channel showing various configurations of Neon.

Cool.

I ordered some green ones as well. If I get the hang of them I think I might do this year's Xmas tree with neon instead of LEDs.

They only need a few milliamps at 90v DC. I used a simple MC34063 driving a step-up transformer, similar to the one in figure 27 in here: http://www.onsemi.com/pub_link/Collateral/AN920-D.PDF but with a different transformer turns ratio.

 

[Fungus]

Try dumping 5-10kV into a neon, WITHOUT a resistor. 

How long do they last?   

[wagon]

Try dumping 5-10kV into a neon, WITHOUT a resistor.  Pretty purple glow instead of orange.  (I repair electric fence energisers, I love to see what their outputs can destroy!)

I tried to destroy an old Pentium using the fence energiser, passing the output through the die using a thin bare coper wire held by the pins on the one side and another on the other side pins. Around 30 zaps, and put it back in the old motherboard, and the bleeding thing posted and booted as if nothing was wrong.  Destroyed it finally by connecting to a 12V battery till the pins melted off, though I was thinking the silicon inside probably was still working.

More power required.  How many joules was the unit?

[wagon]

Try dumping 5-10kV into a neon, WITHOUT a resistor. 

How long do they last?   

I've never run one to destruction.  I should!  I've got a little battery unit on test now, it puts out 11kV open-circuit.  Might run that for a bit.  I've also got a 20+ Joule unit I'm waiting on for parts.  It will blow a 100ohm 10w resistor to pieces, so it'll be good for torturing neons.

Neons are often used in electric fence units to indicate something is coming from the output.  Typically they'll have 100k-200k of resistor in series with the neon.

[Fungus]

Update: The neons arrived today.... haven't got around to lighting one up yet though. I got plain neon plus green and blue phosphors.

nb. The little transformers are just 1:1 isolation transformers from the same seller.  I put them the bag when I was still thinking of connecting them directly to the mains (which I might still do, you never know...)

[Fungus]

Update: I got the little transformers today.

They are indeed a 555 timer feeding a transformer (at about 14kHz). The transformer output is about 177 Volts with a 5V input (yes they work at 5V even though eBay says 6V).

I didn't have any luck connecting neons directly across the transformer output (frequency too high?) so it looks like I have to use DC.

Here's one lighting up some neons connected in parallel across the first capacitor in the Cockroft-Walton multiplier. I need to play around and see how much current it can supply.

Also ... find out if I can connect two neons in series. Can I connect them across two capacitors and get three or more in series, etc.

[Fungus]

PS: The plain orange one flickers up and down the cathode randomly, lighting up about two thirds of the cathode at any given time. It also goes from one side of the cathode to the other.

This is a pleasing effect...  but what causes that? Not enough amps...? Anybody know?

[Fungus]

Update: Three neons in series across the first output capacitor. 



The bad news: The voltage across the cap is much higher than with three in parallel. Was three in parallel dragging the output voltage down already?

[eneuro]

With USB power I could take it down the pub to show it off, etc.

With 12V battery and my ZVS driver driving custom split 5 turn each  flyback primary, secondary a few kV  HV DC easy glows via two 10M resistors in series at low current (below 1mA I guess) 18W T8 0.6 meter long flourescent lamp



I have via those 20M total resistors still 2mm-3mm plasma sparks at very low current, which only slightly turns on 3mm green led, but this huge neon outputs decent light for night lamp from old unused car starter battery, etc.

No need to mess with USB and connect HV stuff close to laptop or desktop PC 

[Fungus]

Now I'm wondering if it might be a good idea to strategically remove caps/diodes and reconfigure the Cockroft-Walton ladder as a bridge rectifier. 

The available power would presumably go up quite a lot.

[alsetalokin4017]

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

 

[eneuro]

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

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

Nice, flyback with removed enclosure? 
Maybe I will multiply flyback output to a few tens kV and energise using my ZVS driver Chrismas tree using plenty such NE-2s?

[alsetalokin4017]

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

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

Nice, flyback with removed enclosure? 
Maybe I will multiply flyback output to a few tens kV and energise using my ZVS driver Chrismas tree using plenty such NE-2s?

Those are regular NE-2 neons. They generally are rated around 1 mW or less in power (0.6 mA is the nominal current that they are designed for, IIRC.)  The transformer is a ferrite core removed from a flyback transformer, with three homemade coils wound onto bobbins that slip onto it. The transistor is a CRT horizontal deflection transistor.
Yes, sure, you should see how many series NE-2s you can light up with a flyback transformer! They explode quite nicely when they get too much current! (Beyond the "purple glow" point....)
You can even light them up wirelessly with the right oscillator and antenna....