5 ms·
Slightly related but a fun thing to learn about was the flashing lights on powerlines (i'm nerdy so love hearing about stuff like this from people in the know).
by AnotherGoodName 3y ago
Slightly related but a fun thing to learn about was the flashing lights on powerlines (i'm nerdy so love hearing about stuff like this from people in the know).
You know those balls they have on powerlines that flash? Easy right? It's just a flashing light. That's what i always thought at least. Until someone pointed out to me that they sit on one line at a time with no earth and no battery, just a capacitor to store charge between blinks. So how do they create a circuit? There's only one wire!
Well since there's current flowing through the wire there's induction and you can wrap that wire in what is essentially half an AC transformer and create a whole new circuit at much lower voltage. In fact the blinking lights on powerlines internally just have two metal plates either side of the slot that goes over the line and clips in. From induction they leach power from the power lines despite there only being one wire and no earth in the whole system.
Which i find really cool and simple. You can take any high voltage power line and a metal plate and power a blinking light just by getting close to it!
- KMag 3y ago> You can take any high voltage power line and a metal plate and power a blinking light just by getting close to it! Well, for high-voltage DC transmission lines (typically used for longer distances to minimize induction loss), you'd presumably need to try to power them via current leaking to the air instead of induction. I'm not sure how feasible that is.
- samatman 3y agoIt gets weirder than that, if you bring a fluorescent bulb close enough to high-voltage transmission lines, it will just glow. https://www.farmanddairy.com/top-stories/how-to-make-a-fluorescent-bulb-glow-under-transmission-power-lines/623730.html https://www.farmanddairy.com/top-stories/how-to-make-a-fluor... Induction is a fact about the physical world which I accept but have never truly understood.
- Izkata 3y agoI remember reading about an experiment years ago where computer chips that could be reconfigured programmatically (FGPAs? Not sure) were put through a genetic algorithm to see if it could come up with a circuit to do a task on its own. In one of the results, the circuit wasn't actually connected end to end so it took them a while to figure out how it worked - turned out the two halves were communicating through induction. I think that same experiment had a configuration that would only work on one chip and not others it was copied to, because it accidentally relied on impurities in one of the components.
- scrlk 3y agoWas it this article? https://www.damninteresting.com/on-the-origin-of-circuits/ https://www.damninteresting.com/on-the-origin-of-circuits/ > "It seems that evolution had not merely selected the best code for the task, it had also advocated those programs which took advantage of the electromagnetic quirks of that specific microchip environment. The five separate logic cells were clearly crucial to the chip’s operation, but they were interacting with the main circuitry through some unorthodox method — most likely via the subtle magnetic fields that are created when electrons flow through circuitry, an effect known as magnetic flux. There was also evidence that the circuit was not relying solely on the transistors’ absolute ON and OFF positions like a typical chip; it was capitalizing upon analogue shades of gray along with the digital black and white."
- Izkata 3y agoYep that's it, I remember this line too: > He also strayed from convention by omitting the system clock, thereby stripping the chip of its ability to synchronize its digital resources in the traditional way.
- ikiris 3y agoIts not about current flowing through the wire, its the fact its an AC line so it has a shifting magnetic field. You can easily extract power from any moving mag field.
- mdavidn 3y agoIf that were true, a DC transformer could not work. It is the flowing current.
- FPGAhacker 3y agoWhat is a DC transformer?
- ikiris 3y agoI suggest you go read how transformers work before you argue with people about how they do.
- scrumper 3y agoTheir confusion is somewhat forgivable when authoritative-seeming but absolute garbage articles like this abound: https://unacademy.com/content/neet-ug/study-material/physics/principle-of-dc-transformer/ https://unacademy.com/content/neet-ug/study-material/physics... This isn’t quite not-even-wrong but it’s not far off being that bad. It’s like a page from that book of false logic that naughty fids have to read in Anathem.
- mdavidn 3y agoAh, I was thinking of a switched DC converter. My mistake.
- mdavidn 3y agoThis is not that dissimilar to how transformers work. High-voltage lines are never physically connected to low-voltage lines. There's always a gap. The circuit in everyone's home ends at the local transformer.