Electromagnetically Lighting a Fluorescent Bulb

As per this video .

If I were to build a simple electromagnet at a distance of ~1/4 inch from the tube:

  • How strong would it have to be?
  • What measurement of the electromagnet’s strength should I be concerned with?

If this were feasible at a ‘homemade’ level, what would be the recommended solenoid length, number of turns, power input, etc?

I’ve only a basic understanding of all things EM, so if I’ve left out any variables, please feel free to fill in the appropriate blanks.


I played the video but it had no sound.

Without that, I have nothing other than a broad idea of what’s happening.

Any more info?

Not much more, other than a rudimentary description of what’s happening on the linking page here .

It’s not exactly an electromagnet, but an induction coil in an induction stove. There’s a coil connected to the contacts on the tube. When that coil/tube assembly is close enough to the coil in the stove, a current is induced in the tube/coil assembly and the tube lights.

In general, induction stoves generate eddy currents in the conductive cooking vessels placed on their surfaces. These eddy currents cause the vessel to get hot, thereby heating the food.

This photo shows a giant grid of fluorescent bulbs standing up under a high-tension power line, and being illuminated by the EM field from the wires! The power required to light the bulb by induction is going to far exceed the amount of power required to light it normally.

If you’re willing to pore through army surplus stores, you might be able to find an old HF radio. Hold the fluorescent bulb parallel to the antenna and transmit on high power. I got a demonstration of this in 1996 and was suitably impressed, as well as having it permanently branded into my brain not to touch an HF radio antenna while it is transmitting on high power.

Interesting. I may have to look into that.

I’m basically creating a showpiece that I’d like to glow without wires leading to it. I had originally thought that it would be easiest to do this with an electromagnet, as I’m already using one in the piece.

I’m thinking the tube (size/brightness yet to be decided) will be about 1/4” away from the magnet, but if there are other ways of doing this, I’m all for that.

Well, it’s not the best approach for demonstrations, as the radio will have a big noisy generator that spins up when you press the push-to-talk switch.

Tesla coils energize flourescent tubes nicely and, depending on the size of the coil, potentially from quite a distance.

Is there any danger in holding up a fluorescent tube while standing under a power line? I’m guessing we’re not talking about freak electrical discharge akin to a lightning bolt. Could the tube burst?

A question: Is this EM field energy lost from such lines on a regular basis? Or are the fluorescents stealing extra energy?

Any time and anywhere there is a conductor carrying an AC or DC current there is an electric field associated with the conductor.
The fluorescents are merely utilizing a very small amount of this energy and procucing light in their own way.

That raises another very good question. I was originally running a DC coil for another part of this, but should I be using an AC to light up the bulb?

I honestly do not know but if anecdotal evidence counts my experience is no…they will not burst. I’ve done this myself and the flourescent buld did not glow all that brightly but it definitely glowed. This was under serious power lines along the lines of those shown in the linked picture but I cannot say how powerful those were and if something more powerful exists to bust the bulb. My guess is no as these power lines seem to be the heaviest duty I am familiar with and I cannot imagine what it would take to overload one but take it FWIW.

I have one of those plasma disks that you can buy at any Walmart, or Spencers. The round, flat disks that discharge filiments of plasma within. If I place that thing anywhere near a flourecent light tube, either in a fixture or out, it lights up. I am certian the plasma balls will do this as well. They are cheap, plentiful, and less dangerous than a HF radio or Tesla coil. You might pick one up and use that for your demo…

I’m pretty sure this is how Nicola Tesla wanted to light homes and transport power - via EM waves.

FYI It is illegal to operate a HF radio transmitter without a license in the US!

Good thing I’m Canadian.

Not for long. Not for long…

Yes, but. If I’m working for the power company, and I look at our meters before and during the time someone sets up these tubes (or, say, several thousand of them), will the meters read a power drain? Or is this just waste EM that is lost all the time, and already accounted for?