Looking for ideas of power source that is highly tolerant of surge/lightening - Page 1
Forum section: electronics / projects

author: tkamiya
author_rank: Super Contributor
timestamp: October 03, 2020, 08:01:54 pm
content: This is a pet project of mine. It may be impractical or even silly but something I've been thinking of experimenting if I can come up with a good idea.The idea is to create a super isolated power source. That is, a power source that is highly tolerant of power surge ether from other appliances or lightening. Something that will do far beyond MOV and spark gap. Power levels are not that demanding. Let's say less than 100 watts, 24V level.So far, I've come up with intense light source and solar panel combination. Drive the light source with mains AC and place a solar panel in front of it.Another is motor and generator combination with coupling made out of isolating material.Yet another is something similar to wireless charging for cell phones. I believe current generation of devices are magnetic coupling? I've seen some white papers using microwave, magnetic flux, and some other exotic method.Another is what I'd call a flying capacitors. Flip a relay to one side and charge. Flip a relay to another side and charge a battery. Keep doing it. At no point, source is directly connected to the battery. (flying)What other possibilities are there? For sake of discussions, I'd appreciate if posters refrain from negative comments such as why this is a stupid idea, how it can be done completely differently, etc. It's not that stage yet. I'm asking for multi-brain involvement in my singular brain brain-storming.Thanks.

author: jfiresto
author_rank: Frequent Contributor
timestamp: October 03, 2020, 08:28:08 pm
content: They tend toward massive, hot and noisy and consequently are not as popular as they used to be, but a ferroresonant line conditioner is very robust.

author: TimFox
author_rank: Super Contributor
timestamp: October 03, 2020, 09:02:13 pm
content: The most extreme example I can think of is what was used at another laboratory to transfer power to a high-voltage terminal, which sat at an elevated potential of 1 MV.The HV terminal was surrounded by SF6insulating gas, and a dielectric waveguide made from high-kceramic passed microwave power from a microwave-oven CW magnetron (on the grounded side of the enclosure) to a dipole and rectifier inside the terminal.

author: tkamiya
author_rank: Super Contributor
timestamp: October 03, 2020, 10:26:06 pm
content: That IS extreme! But makes perfect sense.

author: ptluis
author_rank: Frequent Contributor
timestamp: October 04, 2020, 01:24:20 am
content: Quote from: tkamiya on October 03, 2020, 08:01:54 pmin relation to lightning, let me say to you that if you have the unfortunate moment of a lightning strike your power line, nothing will survive, everything will burn.I know this because of a bad experience in the past.

author: trobbins
author_rank: Frequent Contributor
timestamp: October 04, 2020, 01:37:55 am
content: I think you need to define some practical boundaries, as a huge number of existing facilities manage lightning events in some practical way, and you need to firstly appreciate what forms of management can be applied, and what are practical to implement within the context of what 'system' you are 'designing up' or have a strong interest in.A reference to a voltage and power level does not define where such a power supply is to be located, or the surrounding mechanisms that might come in to play (such as earth potential rise, or electric field strength), or if there is any equipment to be powered from this power supply and how that equipment is connected and to what level that equipment's performance could be influenced by a lightning strike.At the moment your enquiry is very open-ended.

author: coppercone2
author_rank: Super Contributor
timestamp: October 04, 2020, 01:42:45 am
content: I think you will be disappointed by your project, everything you want is expensive and it does nothing usefulwhat fits your criterion : 2 12v lead acid batteries. If you build a battery box its actually useful. A solar panel can be connected to it. FYI usually engineers get annoyed by redundancy to strengthen a design.*not to say a battery box is simple, a battery powered power supply with charging capabilities can be considered a extremely difficult project if approached from the right anglesAnything else that has significant power and continuous capabilities will be expenisve and simple (that is how you make something strong, expensive and simple).

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 04, 2020, 01:45:53 am
content: Quote from: tkamiya on October 03, 2020, 08:01:54 pmFirst of all: can you narrow it down? What specifications are you optimizing for?Example:1. Mains isolation (common mode)2. Mains surge (differential mode)3. Grounding, stability of output with respect to it4. Shielding5. Is this a standalone thing? Does it connect to anything else? Is the connected-thing itself a hazard?Some respective scenarios where these would be relevant:1. Induced lightning, EMP, etc. typically manifest as common mode disturbance; sufficient CM isolation (or attenuation, whether filtering or limiting) is usually adequate. Commercial devices are usually rated 2.5kV here, with medical and industrial devices going to 8kV and beyond. Insulation types range from basic (secondary side is grounded) to reinforced (secondary side is SELV and floating).2. Induced and direct lightning, and other electrical disturbances (from commutating large loads like motors), are common sources of this. Common mitigations being filtering and limiting, and it always helps to have some ride-through survivability. Commercial devices are rated 1.5kV here, with distribution hardware rated for anything up to direct strike (∞ kV).3. If the output is isolated, presumably there should be good (AC signal) isolation from mains, as well as mere galvanic isolation. Is grounding available (a common potential that everything in the system is referenced to)? If so, perhaps the output should be grounded, or at least filtered with respect to it (since again, a galvanically isolated output is handy sometimes). Perhaps neither, and it should just be better shielded from it (example: medical low-capacitance isolation transformers). Perhaps ground itself isn't stable in some sense (compare the abstract idea of ground, to a mains earthing terminal in real wiring), and some (system level?) mitigation is needed, in combination with some of these properties.4. Some system-level mitigation like, building a Faraday cage for a low impedance common ground environment; then all connections entering/exiting the cage must be grounded with respect to it, and filtering/limiting circuits can be applied to susceptible circuits as needed (i.e., mains filtering/protection), keeping things nice and calm within the cage.5. If it's standalone: why bother? At worst, just wrap it with insulation ("double insulated" appliance) and call it good. If it connects to things, perhaps we should ask whether they need any of these considerations instead? Example, computer hardware is usually grounded; if using the Faraday cage system, just tie everything to that. (If ground loops are a problem, say in pro audio -- use differential signalling, or signal isolators.)Not to argue against doing it at all, just a sanity check that we're doing the right thing.Since you're aiming at some kind of possible product, I suppose it's assumed that this is the case, and users will select it, based on their need.QuoteSure, propagating EM waves are doable in many ways. Wireless power can deliver arbitrarily high isolation voltages; in the extreme, I suppose the Sun-Earth system has at most a few billion volts between it, but many petawatts are transmitted from one to the other without shorting out that path.*Transformers are a microcosm of that, being much smaller than a wavelength, so that reflected power can be managed immediately: if the load doesn't draw all the power that the source is capable of, the source can simply not deliver all of it (current or voltage, or a control throttles down automatically).Whereas the other methods, even with some channel to deliver feedback, it can't be done instantly (less than a cycle), it has to propagate out at the speed of light, and the receiver must handle the spare energy it collects in that time, for better or for worse. For example, solar panels simply absorb the excess, dissipating slightly more heat. A microwave rectenna rectifies more voltage, until the peak RF voltage is reached, at which point the load impedance rises suddenly, and power is reflected back out the antenna -- perhaps scattered to the surroundings, perhaps the transmitter has to deal with it at whatever phase it comes back in at.*Which, actually this is a terrible example for several reasons... You can imagine astronomical spheres having various voltages on them I suppose, but who ever talks about their actual voltages, right? But even more than that, the actual value is probably a couple million volts, driven by photoemission of electrons out of one or the others' atmosphere (which therefore can't be more than the energy of the source -- energetic particles at some MeV). Finally, interplanetary space is immersed in a conductive medium, the plasma of the solar wind -- tenuous though it is. So there's a mechanism to drive off charge, in a closed circuit of some finite total resistance.So, you can imagine the spheres having wildly different voltages -- there could be, I don't know, quadrillions of volts between them, if not for all the other physics in play. It's just that there's really very, very little electric field between them, as it turns out.Okay, science lesson aside.QuoteOr a, y'know, battery.Ye Olde cellphone of course has quite high isolation rating, both from power (battery) and signal (WiFi, LTE, etc.).The only difference is the charge curve, and the time constant. A capacitor doesn't store much energy, so it needs to be switched frequently, and for physically-relevant isolation voltages/distances, the mechanical movement severely limits power density. The battery takes hours to charge and discharge, but delivers much more charge at a time (and also at a flatter charging curve: the capacitor C(V) is straight-line, while the battery has an exponential curve).The energy equivalent of "the bandwidth of a station wagon loaded with data tapes".(Or anything else that can be exchanged for energy. A KC-135 moves an awful lot of fuel energy, awfully fast; assuming your isolated location can be flown to.)QuoteSo, for any kinetic means, you must have real power. At DC, you need voltage and current; at AC, you need voltage and current in phase. And this works for any system that has these properties.Examples:Linear mechanics: force alone, or velocity alone, will not do; you must have force times velocity, in the same direction. So, a mass pulling down on a cable, but not a mass swinging in a circle.Rotating mechanics: RPM and torque. Pneumatics, hydraulics: pressure and flow rate.Oscillating mechanics: force/torque in phase with linear/angular velocity.Acoustics: pressure in phase with flow rate.Potential energy sources include fuel, as mentioned, but also flying capacitors, flying inductors (the flyback converter is an almost overly simple example, but I would argue it's a potential energy mechanism), anything that stores or accumulates power.Less reversible sources include fuel of course, which must be mined, or synthesized somehow or another; or primary cells, which must be constructed and cannot be recharged (aside from recycling and starting over anew).A mechanism you may not be aware of, but which is actually commercially available: acoustic coupling. Piezo transformers are a thing! They aren't great "transformers", because of the above mentioned reason -- propagation along them is much longer than the cycle time; you can't model one as a nonideal transformer. It's a bit of a misnomer. I think they're still okay to model as coupled resonators though. (I haven't played with one, mind.) Which would make them similar to other loosely-coupled resonant systems, like wireless charging.Tim

author: tkamiya
author_rank: Super Contributor
timestamp: October 04, 2020, 02:34:54 am
content: Yes. My post is very open-ended and broad. That's on purpose. I don't want to narrow possibilities too much when the project is in brain-storming stage.As to if I get a direct hit, nothing will survive.... that's not true at all. Cell sites, radio towers, and tall commercial buildings get hit by lightening all the time. Yet, they survive most of the time. My former work place was like this. Tens of millions of dollars of computer equipment in middle of Florida. What they do is spend huge amount of $$ in consulting and have a custom and complete lightening abating system. We did get a direct hit one time. Corner of our building was hit and pretty big chunk evaporated. Now, realistically, my personal budget won't allow this. So I'm looking for a limited protection. But, getting a direct hit and surviving is technically very feasible.I appreciate all of the input. I'm not trying to create an ultimate scientific achievement. My scope is very limited. It seems solar charged battery would fit my criteria, given there is enough excess storage. Thanks for the reminder, simple solution does exist.

author: tkamiya
author_rank: Super Contributor
timestamp: October 04, 2020, 02:49:27 am
content: I'm actually curious. Some of us have a huge cache of test equipment in our labs. I do, too.... 6 racks worth of HP and Tek stuff, mostly. It represents a pretty good investment if we were still in 1980sOf course, I bought each of them for pennies on a dollar, or sometimes less. But I digress..... For realistic protection, I have a multi-stage of whole-house surge protectors and local to each rack protections as well as beefed up grounding system. Power distribution in our area is underground. So far, so good.What prompted my "quest" was, power lines aren't the only way lightening energy can come in. Cable TV, internet connections, and telephone lines can all do the same. I was going to do fiber optic lines for internet connection, but it still leaves a need to power optical/Ethernet conversion device, which will have to make connection to the mains. Now, there is a single power surge protection device (provided by cable provider) in place. I want to do more than just that.What do you do? (addressing everyone) Do you not have lightening damages on your mind? What practical preventative measures do you take?

author: T3sl4co1l
author_rank: Super Contributor
timestamp: October 04, 2020, 04:46:37 am
content: I don't worry about it. The risk is very low, and the likely affected items can be replaced easily.I do have a surge protector power strip, which may not even be working anymore (it's even the kind with the detector lights, but they're neon which degrade over time!). Cable modem is utility supplied, router is unlikely to be damaged (thanks to Ethernet's isolation) and not very expensive anyway. PC, test equipment, other appliances: nothing that can't be replaced. My data can't be replaced, but it's backed up and hard drives are fairly unlikely to fry from a surge event anyway.Interestingly, I do actually have an example; not personal, but my parents had a surge a year ago, apparently a lightning strike to a tree or pole in the neighborhood. The induced surge (EMP or conducted) was enough to blow out a few odd devices; like, the cable modem I think was alright, but one router died, and a, I forget what else, a TV or something? It was kind of an odd combination of things, and not all the "front line" (connected to utilities) equipment. Presumably, some combination of power lines, or cable, or the haphazard routing of Ethernet lines between them, conspired to generate enough loop voltage that those things got fried, and those just happened to be on the worst loops, or happened to be the poorest equipment (low breakdown voltage, relative susceptibility, etc.).If a strike gets much closer than that, I think you'll have bigger things to worry about, not so much the destruction of electronics as the burning down of your house, or a tree falling on it!Tim

author: coppercone2
author_rank: Super Contributor
timestamp: October 04, 2020, 04:53:16 am
content: you can put a surge arrestor on the coaxial line before it goes into the modem, I think the goal would be to limit the damage to the communications cards in the equipment that is connected, and hopefully limit it to a dead routerFrom experience I had damage that effected the bios, fried the NICs, fried the modem and router.. the motherboard still worked only had damage to the character ROM (bad chars). This was from a lightning strike 20? feet away from the house. This was the damage that occurred with no protection. (no power strip, anything else). I think the cordless phone base was OK, only computer equipment really suffered.. the other stuff is built a little tougher I think.So something you can do: buy a NIC card and not use the onboard NIC for your computer, so you can most likely swap a card out instead of a motherboard. (all the on-board stuff can cost you money..)

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 04, 2020, 07:34:53 am
content: The methods you listed are good, they are really able to protect the energy consumer. But the primary chain will still not resist the lightning and will be destroyed. Lightning is a huge voltage and incredible energy, there is no recoverable protection from it.

author: trobbins
author_rank: Frequent Contributor
timestamp: October 04, 2020, 10:46:58 am
content: Are you prone at the moment? You said you have underground power. The other basic queries are: do you live on a hill? do you have tall structures nearby? Do you have a detached house? Do you know all the incoming metallic conductors to your house, and do they have accessible connection/interfaces where they enter the house? What protection is on each and every incoming conductor (you indicated you have cable and that has a protector but not where that is or where any fault current flows)?It is very easy to add in local protectors to various bits and bobs of equipment, but have no clue as to what the basic fault current path is, or how it will all interact depending on the method of surge entry. Are you interested in your own life, or just the equipment's health so that it can sell for a good price on ebay if you get zapped?

author: tkamiya
author_rank: Super Contributor
timestamp: October 04, 2020, 10:53:46 am
content: Excuse me? Am I interested in my own life? That's really is uncalled for.

author: tkamiya
author_rank: Super Contributor
timestamp: October 04, 2020, 10:58:05 am
content: Tim, I also have a very similar story.Back in my younger days, I was living in a two story apartment. Apparently, there was a near by strike. A CB antenna I had on my balcony had tip and base partially melted. Antenna itself was a stainless steel and base was thick aluminum. TV died but VCR survived. Phone died. Computer lived but modem got fried. Few odds and bits lived and died. I guess such is a random nature of lightening damages. I wasn't at home when this happened, so I never got to learn how and what happened.

author: S. Petrukhin
author_rank: Super Contributor
timestamp: October 04, 2020, 11:18:56 am
content: This is an old Soviet film about lightning and protection from them. If you don't understand Russian, turn on subtitles with translation.

author: trobbins
author_rank: Frequent Contributor
timestamp: October 04, 2020, 11:44:32 am
content: Quote from: tkamiya on October 04, 2020, 10:53:46 amDifferent outcomes often have different protection level targets, which often use different protection setups and device selections. You may unknowingly add protection with the aim of saving the equipment without realising you yourself were still prone or possibly were more prone (because you didn't protect one metallic input line such as a phone, and somehow worsened the prospective EPR between the phone line and anything else in your house, of which you then bridged).