Some fun facts to make things lighter.... Have you heard of the Corona Effect? No I'm not talking about the virus sweeping the world. This is something related to electric transmission. During transmission of EHV(Extremely High Voltage), say upwards of 132 Kilo Volts, you'd find a bright bluish purple haze over the transmission towers right where it carries the conducting wires mostly on rainy or humid nights. That's what we electrical engineers call corona. It happens because the extremely high voltage within a short gap between two conductors, causes the air between the conductors to breakdown and become partially conductive. (Air is normally non conductor of electricity but the high voltage over a short gap is able to ionize the air, causing occasional sparks to pass, that's why you get to hear the zooming sound when you walk below a transmission tower). The air on ionization can even release gases like ozone and nitric oxide. It might look pretty but it causes substantial loss in the electrical network unless we take preventive measures like using corona-rings, increasing the space between two wires etc. Here's a picture of it. See if you have ever noticed it. Or next time just keep a look out for these pretty thingies. 馃檪
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@ABCDEF7 Yes, kind of. Tesla coils also involve some other principles like transformation of electromagnetic energy between the primary and the secondary (the longitudinal coil with a dome on it that you generally see) to magnify the voltage level, but at the end of the day, it basically boils down to breaching the breakdown point of air and making it somewhat conductive for sparks to pass.
@ABCDEF7 I don't know which cfls you've seen on YouTube but cfl works on a different principle. It consists of mercury atoms which when excited by a small amount of electricity releases electrons, and when this source of excitation is removed the electrons fall back to the stable state, emitting UV. This UV gets absorbed by phosphorus in the cfl and emits light that we see. Here it involves ionization of mercury / other inert gases present inside the lamp to facilitate flow of spark. A different concept. High voltage is not involved here.
Thanks for your efforts to explain me the concepts. I am not clear how it's happening in background in these videos, as the person is holding the lamp in his hands. I guess it's transfer of energy through electromagnetic induction(as in transformers), and there is something like hidden secondary coil inside CFL.
Sorry for my ignorance and bearing with me, I am not a science graduate, I have been a commerce student, and an IT professional, just have little curiosity about how things work.
@ABCDEF7 That's alright. Even I don't know everything about my own field and anyone who claims to know everything is a fool. The videos you linked are basically DIYs for mini tesla coils, they don't show the working principle of cfl. The cfl works as I said before. You've just got to provide electricity to the input points of the cfl(the part that goes into the holder). What they show in this video is that the Tesla coil produces energy that radiates over a space around the coil. Which means, as I said earlier, it breaks the air down around itself into a somewhat conductive element and hence electricity conducts through air (which is what we call wireless). This electricity, when it goes through the input sockets of the cfl, makes it work on the principle I mentioned above.
@TheIncredibleHulka Thankyou very much, that's how they say it works, but I have a questions that may sound stupid to you.
Why the cfl glows, and not burst/fuse due to short circuit. What is making the electricity to choose only one terminal of cfl, not both? How do it choose that one?
Why that wireless electricity not burning the much sensitive electronics parts inside CFL holder, like capacitors, transformers, diodes, etc.
How the other input/terminal of CFL is getting the ground/neutral to complete the circuit?
When I didn't got the answer to these questions, I thought of the possibility of glowing of cfl due to ionisation of mercury/other gases as you mentioned.
@ABCDEF7 Why should the cfl burst? There's no short circuit. The glow is due to the atom [i][b]returning to the stable state when it loses energy and emits UV light[/b][/i]. The cfl may burst if the spark leaks through its body due to faulty manufacturing. Of course the electricity is being picked up by both the input terminals. It's AC, so the current changes polarity in a cyclic manner and therefore interchanging of terminals don't matter. A valid point, the energy generated by the Tesla Coil is erratic, uncontrolled, which is why we don't use it widely as a source of "free energy". If used, it would fry almost all sensitive equipments in it's proximity like mobile phones, computers etc., not to mention the huge RF field that'll create a different havoc. However these are mini tesla coils with low power and while there are chances of what you said occurring, it usually doesn't. Ground and neutral are two different things, often confused as the same. A neutral is a return path for the current. Ground is when you connect this neutral to the earth or ground for safety. A neutral may or may not be grounded. Presence of a neutral or return path is sufficient to complete the circuit for current to flow, it might not necessarily be grounded. If you hold a cfl terminal in your hand, you'll see it has two terminals, one of them act as the forward path and the other as the return path, in this case, it doesn't matter as the electricity is AC and changes polarity anyway. Hope this answers your query.
@TheIncredibleHulka Thanks for explaining, I had some idea about the difference in neutral and ground. But I still have doubt how the current is getting it's return path(neutral). My doubt about about cfl getting burst was due to the reason if we connect both terminals of it with live supply, as that might happen in wireless electricity, as the both terminals are nearby.
I am sure I am still lacking understanding of few fundamentals. I am sorry if I am getting irritating for you.
@ABCDEF7 Okay, I get your query. Electricity will always choose the path with the least resistance, in other words, electricity will always choose the best conductor. Now air is a non conductor, however much you breakdown the air, it's still a poorer conductor than an aluminum/copper strip. So current will always choose the aluminum path rather than travel through air to the other terminal and short the terminals,unless you physically connect the two terminals with a strip of wire creating a short circuit. Here's a rough sketch I've drawn which might help.
The terminals of the cfl are in any way encased in insulators so that one terminal is well insulated from the other,so there's no chance of breaching the insulation at least with these mini tesla coils. Although a powerful HV tesla coil generating huge energy might break it down causing a short circuit, as I said before.
@TheIncredibleHulka First of all, thankyou very much for the effort you are taking for a stranger.
If that's so, why don't my bulb at home stops to glow when there's somewhere neutral wire broken? I need to manually repair it. An possible reason I can think is voltage at home is not that much higher to breakdown the air. And in this case it is too high. Is that so?
And why not that wireless electricity finding the way through that person. He is also connected to same air.
And finally I still not convinced why that wireless electricity choosing only one cfl terminal at a particular point of time. I am really sorry for my ignorance and inability to understand concepts. I hope you are not getting irritated with my questions.
@ABCDEF7 I didn't get your question involving the bulb. The bulb will stop glowing when the circuit inside breaks, breaking the path of the current.
A person is a poorer conductor of electricity than a metal,unless the person is touching an unearthed metal body,electricity won't flow through his body.
And finally, electricity does flow through both the terminals, but with opposite polarity, the polarity reverses at very frequent intervals (frequency of 50-60Hz mean 50-60 cycles/reversals per second, tesla coils generate higher frequency) which makes no difference at all however you may define your instant.
I'm sorry I did my best in explaining, perhaps this is why we all need teachers and years of dedicated studying on a branch to get proper hold on any subject.
@TheIncredibleHulka Thankyou very much for all your efforts. You helped me with many of the concepts. I will discuss these things in detail with my colleague once the lockdown is over.
