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TC driving Fluoro string. How long?

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LAN_403

Tesladownunder

Tue Apr 07 2009, 07:45PM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

I have hooked up a string of a dozen fluoro tubes to my TC. Worked fine but how long a string do you think can be run? I have about 100 fluoro tubes (the hospital saved their dead tubes for me) and a long driveway.

GeordieBoy

Tue Apr 07 2009, 07:58PM

Registered Member #1232 Joined: Wed Jan 16 2008, 10:53PM
Location: Doon tha Toon!
Posts: 881

That is way cool Peter!

To answer the "how long?" question...

The voltage drop of each tube is probably a couple of hundred volts maximum. And your TC might generate a couple of hundred kilovolts. So I guess the short answer is about a thousand tubes! I hope you have a real loooooong driveway! Hmm, maybe you could branch out into streetlighting as well?

In practice i'd imagine the AC current driving the string of tubes will gradually leak away to the nearby ground by capacitive coupling. So the tubes will likely get dimmer the further they are from the AC source. There may also be some electromagnetic radiation if the string of tubes gets to be a significant portion of a wavelength at the TC's resonant frequency! Plasma antenna anyone!?!?

-Richie,

aonomus

Tue Apr 07 2009, 08:39PM

Registered Member #1497 Joined: Thu May 22 2008, 05:24AM
Location: Toronto, Ontario, Canada
Posts: 801

I wonder if this is a lead up to a new TDU photo....

Try making a birds eye view fractal with the tubes :D

MRacerxdl

Tue Apr 07 2009, 10:18PM

Registered Member #989 Joined: Sat Sept 08 2007, 02:15AM
Location: SÃ£o Paulo, Brazil
Posts: 476

Very interesting, once, I was thinking about make that test with a NST, but I didnt get much lamps to see what is the maximum that I can series it... Good luck !

Alexandre

Tue Apr 07 2009, 10:32PM

Registered Member #1228 Joined: Tue Jan 15 2008, 01:08AM
Location: Curitiba, Brazil
Posts: 162

hmmmmmm

I will try to do this with my larger coil, good idea!!!

aonomus

Tue Apr 07 2009, 11:43PM

Registered Member #1497 Joined: Thu May 22 2008, 05:24AM
Location: Toronto, Ontario, Canada
Posts: 801

Another thought you could do is if you had a audio modulated DRSSTC, you could make a brutish VU meter based on distance of tube to coil...

Tesladownunder

Wed Apr 08 2009, 12:28AM

Registered Member #10 Joined: Thu Feb 02 2006, 09:45AM
Location: Bunbury, Australia
Posts: 1424

The answer of how many tubes is not an easy or trivial one and will not be 100+. Just look at how weak the 1 foot spark is at the end of this string on the enlarged pic.
If you simply connect it to the end of the TC it will be seriously detuned. I have used breakout points for past projects up to perhaps 30 feet long which reaches the limit of my tuning on either coil. Then there is the cumulative corona loss.
Individual initial breakdown of a tube might be a kV or so but unclear whether it drops for the next cycle in the absence of filament heating as in normal 240V operation.
Any thoughts? I might extend the string over Easter.
The first run I did in the day time. Big mistake. I couldn't see the arc to ground in the middle of the string that melted my nylon rope. I smashed 5 tubes when it parted.

1239150293 10 FT67192 Teslafluorosendspark

hotcrazyfruit

Wed Apr 08 2009, 02:14AM

banned on 5/26/2009
Registered Member #1877 Joined: Mon Dec 22 2008, 02:03AM
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Posts: 147

i say you keep goin.... wont it just stop glowing at the maximum number of tubes it can light up?

GeordieBoy

Wed Apr 08 2009, 12:23PM

Registered Member #1232 Joined: Wed Jan 16 2008, 10:53PM
Location: Doon tha Toon!
Posts: 881

I think you'll get the longest length of tubes if you connect them together with wires and firmly connect the end of the last tube to ground. The distance will be limited if you leave the end of the last tube to arc a few feet to ground because this requires a lot of voltage to do so. At the end of the line of tubes there will likely be very little voltage left due to the volt-drop of the tubes and also due to the capacitive current leaking away to ground all the way along the line!

Of course it will detune the TC massively. One the tubes strike they are very conductive, so it's almost like hanging a long wire from the toroid, or like having a much bigger toroid. You'll have to tap out on the primary or add more primary capacitance to compensate. In the end you might find that you have to tune the primary so much lower that the system is can never actually pull into tune and the tubes never strike!

I for one am interested to see how many tubes you can light in series!

-Richie,

Avalanche

Wed Apr 08 2009, 04:59PM

Registered Member #103 Joined: Thu Feb 09 2006, 08:16PM
Location: Derby, UK
Posts: 845

That looks awesome, I also vote more tubes, being as you said you have 100

It could even become a permanent feature along your drive?!

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