Driving dead tubes via induction

[lasagafield]

A few years ago I made a tesla coil and had a lot of fun waving fluorescent tubes in a few feet of it's radius watching them light up.
As I've recently started looking at T17 gear I started reading more on electrode-less fluorescents and got the idea.
Would it not be possible to build an induction driver to light up dead tubes?
I don't expect one to light them up very well but if a fitting could be build that would drive the tubes in some way so what?
Say you've got an old burnt out BC that hasn't gassed.
Could you not build a dummy fitting and drive the tube wirelessly and gently enough to not cause damage to the electrodes at either end?

[Ash]

I'd try to wrap Aluminum foil sections around 2 areas of the tube. Better yet the sticky Aluminum tape like what's used on ducts (not duct tape), as that makes very tight contact with everything (which makes it useful for EMI shielding and stuff like that). Tight contact with the tube seems to make difference in 50Hz based applications (like brushing a tube that won't start on RS or SRS)

Since the coupling is capacitive, it gotta be HF AC and i'd guess on the order of few kV (Tesla coil output is ok)

[lasagafield]

Thanks, i'll give it a go when I get the gear and let you know how it goes.

[Zelandeth]

Interesting idea.

The Osram Endura induction lamps are essentially doing just this (and the bunch of Chinese clones of the same style), so surely it can work.

Be interesting to see if one of the drivers from then would work....if I had a broken one floating around I'd definitely have to try it.

[lasagafield]

I do know that the big fat 150w induction ones do have a lot of mercury in them. A lot more than a typical linear fluorescent.
However if you have a knackered one and you can lob off the ferrite ring windings they'd be a good place to start messing about with.

[Ash]

Different operation principle there

What we propose here is coupling the current into the tube through capacitance. The discharge is in series with 2 capacitors, that are formed by the foil (one plate), the tube Glass (dielectric), and the tube fill (other plate)

In the Endura/clones the coupling is inductive. The Ferrite core, coil and the tube form a transformer, in which the coil is the primary winding and the tube (essentially a shorted single turn) is a secondary

To make an Endura like setup the tube must be a closed loop. You can slip ferrites on any tube and then short it's electrodes with a wire, but then you miss the point of being electrodeless..

[lasagafield]

Ah, I see.
Well it's back to plan A then.

[Flurofan96]

Got an EOL 2D 28W lamp that can be the one for this experiment as I did the plasma ball test and it lit up pretty bright