# Capacitor to store lightning?

Discussion in 'General Science & Technology' started by cato, Sep 21, 2004.

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1. ### phlogisticianBannedBanned

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Because a cloud at a lower potential looks like the Earth. Lightning wants to find Earth, from an ELECTRICAL point of view, Benny, Surely, you, with your certificate in Electronics, understand that an Earth is not always connected to the Earth?

3. ### JTWashRegistered Senior Member

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BennyF is David Cain

That video you linked to is from the actual TexasDave, a Yahoo poster David/BennyF is obsessed with, going so far as to create a similar Yahoo ID to impersonate the real TD.

Gentleman, responding to BennyF is going to get you nowhere. He's an internet forums troll looking for attention. As I posted earlier, he pollutes the Yahoo boards with absolute nonsense. He's completely ignorant of the mortgage industry, but he'll try and 'correct' and 'teach' those in the actual business. He actually thought a stock that is currently trading for around .50 a share was going to hit a million dollars a share:

"A million dollars a share [FBC]! Someone has placed an order to sell 100 shares at that price. Can't help but smile at the thought of how soon it could happen, with earnings blowouts, upgrades, dividends, and the inevitable merger talk." - David Cain/Vette, 14-Oct-09, from the Delusional Series

Some of you have tried to teach and educate him, and for that I salute you. However, it is a wasted effort. David/BennyF has no interest in learning or discussing any topic in an intelligent manner. He's here for the attention and to make himself feel important. I tried to educated David/BennyF about the mortgage industry when I first encountered him on the Yahoo board, but he would have none of it. In David/BennyF's world, he's the only learned expert and we are all ignorant wretches.

Oh, he has a God complex as well, believing himself to be a messenger from the Almighty. He even posted something to that effect early on in this thread. Truth of the matter is that this whole lightning catching scheme was hatched in his head when he ran across a Wired article back in 2007. He has and never will apply for a patent because all of this resides in his fantasy land. We've been waiting for a patent update over on the Yahoo boards for over 4 years.

Good luck dealing with BennyF - He'll create new IDs soon enough and will begin responding to himself on this board in an attempt to drown out dissent and those that point out his ignorance.

5. ### phlogisticianBannedBanned

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Yes you do, you need to prove you graduated from that course like you claimed you did. So far you haven't shown us anything. Apart from ignorance.

7. ### BennyFRegistered Senior Member

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I'm an admirer of Mr. Franklin and Mr. Edison. I am an amateur inventor with a 90% complete application for a US Patent, and I am quickly getting bored with you playing the role of an amateur detective. Adjust to your new role as an amateur scientist or you may find yourself in a place that is spoken about in hushed tones by some of the most revered philosophers in history, the world of Limbo.

8. ### phlogisticianBannedBanned

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I've already had my answer Benny, I now know it's a guy you impersonate on other fora.

Now, how about you show us that qualification?

9. ### BennyFRegistered Senior Member

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Good-bye, Phil. Welcome to Limbo.

10. ### phlogisticianBannedBanned

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10,342
Now, how about you show us that qualification?

11. ### MacGyver1968Fixin' Shit that Ain't BrokeValued Senior Member

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Ok..."blew up" maybe a little dramatic...more like "smoked". So I was working for a tanning bed manufacturer that wanted to come out with a new model...a "super" bed...and I was put in charge of designing the power systems. The top of the bed, by itself had 51 160w florescent lamps, and 4 2000w quartz facial lamps. Each of the lamps had it's own ballast and a capacitor the size of a beer can. The problem I was having was on startup, the caps would draw so much surge current as they charged, they would cause arcing across the contacts of the main power relay as the contacts closed. This arcing would literally weld the relay closed, and you couldn't turn off the bed.

The morning I was supposed to demonstrate the new bed to the big wigs, I was running some tests and welded another relay closed. I had to quickly replace the relay before the big wigs showed up. The relay had 4 gauge wire as big as your finger running into and out of it. Since I only had one spool of this wire, both leads were the same color. In my haste, I accidentally reversed the polarity of the wires. When I finally turned the bed on in front of them, I had a direct short circuit across the relay, and WHOOSH!!!! Sparks flew everywhere and smoke poured from the bed as the 4 gauge wire melted itself. It was a sight to see. Fortunately the big wigs were cool, and had a good laugh at my expense. I replaced everything that fried, and later that day successfully demonstrated the bed. I eventually overcame the relay welding problem by using 2 separate relays for the florescent and quartz lamps.

The point of the story, Benny...is that you can't always anticipate everything that's going to happen with real world components (welded relays).

12. ### billvonValued Senior Member

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Not really. We generate no voltage to speak of. There's static electricity (stored charge) which accumulates and is equipotential throughout our bodies, and there's active differential potentials caused by neural and muscular activity - but those are measured in millivolts, not volts. Decades of EKG and EEG designers have verified this.

Well, if you've ever seen a spark from your fingers that's 1/4 inch long, that's between 5 and 15kV of potential.

13. ### BennyFRegistered Senior Member

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Your story is much better written than Phil's, I have to admit, and it has some similarities with Tom Clancy's stories because they're both based on science.

Your point is taken. I'll do the breadboard testing on my circuit before I send in the application to the patent office. Now that I found out about the change in the patent laws, I was going to wait until after the U.S. became a first-to-file country anyway.

If I might humbly ask a question or two ....

Why didn't you distinguish the two 4-gauge wires from each other somehow, perhaps by putting some 50-cent electrical tape on one of them? It's been said more than once that low-tech solutions sometimes solve high-tech problems.

And why didn't you have some way to cut the power to the whole contraption, either manually (pull the plug) or with some sort of current-overload circuitry?

14. ### MacGyver1968Fixin' Shit that Ain't BrokeValued Senior Member

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In hindsight..that probably would have been a good idea, and prevented me from hooking up the "neutral" input wire to the "hot" output terminal of the relay.

The bed pulled too much current to use a plug..it had to be hardwired into the circuit. Everytime the relay would weld closed, I would have to walk over to the circuit breaker box, and turn it off there.

15. ### BennyFRegistered Senior Member

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This is interesting from the point of view of an amateur electrician. If the bed didn't get its' power from a wall outlet, what was the source?

Please tell me that you didn't use your portable nuclear power plant. I didn't want the details to be revealed until after I could write my own sci-fi story and have it incorporated into an artillery-sized death ray.

16. ### MacGyver1968Fixin' Shit that Ain't BrokeValued Senior Member

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They don't really make plugs or outlets that can handle 220v @ 80 amps. The power cable for the bed was hardwired directly into a 220v/200 amp sub-panel breaker box. It's one reason it blew up so spectacularly...it took a couple of seconds for the breaker to throw.

17. ### BennyFRegistered Senior Member

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Call me a Monday-morning quarterback, but I still think that something should have been designed and built in, so that in case of an emergency (like a current surge), the power could have been cut.

Maybe you could have found a fuse that was rated for those specs. If nothing else worked, could you have inserted a small-gauge wire somewhere in a high-current circuit, knowing that it would heat up and melt long before anything more serious was damaged? Like I said, sometimes a high-tech problem has a low-tech solution.

Hey! This reminds me, lightning is also a surge in current! Tens of thousands of amps! I'd better design some way of handling it before it melts my own relays!

Last edited: Sep 13, 2011
18. ### MacGyver1968Fixin' Shit that Ain't BrokeValued Senior Member

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This was a "one of" prototype that was still in development. The reason it blew up was because of a stupid wiring mistake by me...a mistake that would never make it out the door on a production model. There was no need for a fuse or small gauge wire (laughing), that's what the circuit breaker is for. Production models would be hooked up to an appropriately sized circuit breaker for protection.(the final design used 2 power cables connected to 2 smaller breakers to help reduce the installation cost for the customer) Since this was a testing prototype, I had to connect to the only circuit in the building that had enough ampacity to run it...a 200 amp breaker....much bigger than it should have been.

19. ### BennyFRegistered Senior Member

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This is a serious question, MacGyver, and I want a serious answer.

If your circuit breaker took a few seconds to "kick in", then can you really say that it was doing its' job? After all is said and done, a prototype that you said cost $50,000 WAS damaged. Wouldn't the dollar value of it alone require more protection than it got? Also, couldn't a small-gauge wire in the right place, doing what a fuse does, and costing a heck of a lot less than your relays, have prevented the damage? The gauge wouldn't have to be as small as what I used in the breadboarding labs in my school, but something small enough to disrupt any high current before it could damage a relay or the$50,000 tanning bed.

By the way, there's an easy way to prevent the peak current of a lightning bolt from damaging any cap bank. If you know that the wire leading into it can handle, say 1 KA, then design and build into your circuit a wire than carry 1 KA. Then, later in the lightning strike (I know, the whole thing is over in a few seconds), when the current level goes much higher than that, your 1 KA wire will burn out and protect your valuable caps.

Last edited: Sep 13, 2011
20. ### billvonValued Senior Member

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Yes. Circuit breakers do not prevent damage; they prevent fires. (Which is why the National Electrical Code was written by the National Fire Prevention Association.)

Perhaps. A lot of things seem wiser in hindsight.

On the other hand, if one out of every 50 prototypes is damaged due to lack of protection, and additional circuit protection would take more time and money - it might well be worth it to occasionally lose a prototype. We usually don't use fuses and/or breakers on our prototypes, although we occasionally lose one to overload.

Smaller gauge wires have higher resistance and generate more heat during operation. Very small calibrated lengths (i.e. fusible links) can work for simple low-efficiency applications, but fuses or breakers almost always give you better performance.

Problem is that there is a very wide gap between a wire gauge that will safely carry a given load and a wire gauge that is guaranteed to fail by opening under an overload.

In addition, under conditions of high current and voltage, just melting a short section of wire won't stop the current flow, since an arc will form. High voltage/high current breakers have complex arrangements of insulators and blowout magnets to quench the arc and stop the current flow.

21. ### MacGyver1968Fixin' Shit that Ain't BrokeValued Senior Member

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The only thing that was damaged was a couple feet of wire and relay. (and my pride.) This was a prototype that was temporary hooked up for testing only. If it had been connected to a proper sized breaker, the breaker would have thrown as soon as I turned it on, and nothing would have happened...but I had to use what was available to me at the time.

As JT said:
You're doing just that. Even though you have zero experience with tanning bed design and testing...or any experience in high current AC devices...you are attempting to lecture me on what I should have done. Your suggestion of using a small gauge wire as some sort of fuse shows exactly how little you know on the subject. Please stop trying to teach...and try starting to learn.

I just shared a personal anecdote to show you not everything goes as planned.

22. ### BennyFRegistered Senior Member

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And the NEC is only updated once every three years. I've seen it. Meanwhile, if a circuit breaker cannot prevent a cap (or a bank of them) from being damaged due to a current surge, then a wise circuit designer will specify something else.

If your primary safety goal is to prevent a fire, yes, but if your primary safety goal is to save some expensive capacitors from electrical damage, then something else will have to be used.

Then maybe the small-gauge wire will be a long section of wire, something long enough so that an arc can't form.

As for the question of using a small-gauge wire at all, lightning has such a dramatic jump in the voltage and the current that it's worthwhile to design in some sort of safety features, just to protect whatever valuable assets (house, commercial property, capacitor bank) you own. When you expect the current to rise to tens of thousands of amps on your first lightning strike, couldn't you insert a small-gauge wire in between the cap bank and the lightning rod, knowing that sometime before the amperage reaches 20 KA, it will overheat and burn out?

I want to remind you, just in case you forgot, that this is a theoretical question for me. The circuitry I will try to patent is not a cap bank, it's just a method of charging a single cap.

Benny

23. ### billvonValued Senior Member

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"Only?" That's remarkably rapid for a document that basic to construction, and causes a lot of consternation for electricians.

Well, that's not a safety goal, it's an economic goal. But yes, there are lots of options for protection.

Then your losses will be horrific. A long small gauge wire will have a lot of resistance and transform most of the power into heat.

I don't think you realize just how much current and voltage that is. If you open a ten foot section of wire, the energy will jump the gap. (Keep in mind that it just jumped a few miles of air.) About all you're going to be able to do is connect a secondary ground to divert all that energy to ground.