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.
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.
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?
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.
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…
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?