Electrical questions for armor.

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fullmetal56

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So I've been thinking about how I've seen a lot of people using straps to connect their armor pieces and to be honest I have no interest in doing that. I have an idea, and if anyone with knowledge in electrical engineering could answer some questions for me it would be greatly appreciated.

So here is the basic concept. Instead of using straps, I was thinking about creating a "grid", (if you will), inside of an under suit, (which has yet to be made), of wires and washers that would connect to batteries in the back armor piece. Also stored in the back piece would be a small series of tesla coils to up the voltage from the batteries. Now, in my head at least, this should create a series of extremely powerful electromagnets to which washers mounted inside each armor piece could connect to and not fall off. Much like wrapping a wire around a screwdriver and connected to a battery would create a magnetic screwdriver. This would potentially be far cheaper than buying a bunch of magnets and with the tesla coil upping the voltage it would be way more powerful.

So my questions are really , would this work? What flaws are there? About how long would it last connected to a 12 volt battery or say 10 AA batteries? Any kind of input would be spectacular.
 
Look up Ampere's Law.

1) Voltage has no direct influence on magnetic flux, so firing a 555 through a IGBT isn't gonna solve anything. Plus, that produces an HF square wave, and you need DC for a functional electromagnet. You could, I suppose, but it through some kind of full-bridge rectifier, but the current required to run an electromagnet off your secondary will either fry or thermal cut-off your IGBTs/MOSFETS. You'd need some seriously huge, expensive transistors.

2) All things being equal your primary factors are coil windings and current. The more windings you have, the more they're contributing to the flux, but this also increases your wire length and therefore your resistance. Resistance reduces current at constant voltage, so you either need more voltage or thicker wire- Ohm's Law. There's a good chance the thickness of wire you need would make the number of windings you want impossible, so this requires compromise. If you left the wire as-is but increased the voltage to increase the current, you've also increased the power, which is going to result in overheating. So you're still required to increase the wire diameter and therefore coil size.

3) Even if you get a huge, heavy coil winding AND you have some crazy expensive IGBT rig to throw enough voltage and current through it, there's no way in hell this thing's going to run off battery power for more than a few minutes, and then your armour all falls off. The puny electromagnets you see in toy kits aren't going to hold armour up and withstand the instantaneous forces of movement and jostling, and even the smallish solenoids pull a lot more current than you'd think, so even if you killed the HV idea, it's still gonna kill batteries in minutes.

4) Even if you think that would be the most awesome thing ever for a couple of minutes, without extremely bulky high voltage high frequency insulation, probably bigger by itself than your suit, your Tesla coils arc through you and into the ground and you're dead under a tenth of a second after turning it on.


TL;DR: Nope.
 
I think I know what you want to do, but I'm not sure it it would be very practical. It's been a while since I've worked with Tesla coils, but I know they do produce an elctromagnetic field. I'm not sure ones so small would produce a very strong field though, not only that but you'd want to keep it facing up and away from your body, making the gap between you and your armor pieces very far apart. While it would be nice to have a switch to flip and turn off the magnetic field, I think your best bet would be rare earth magnets. They'd most likely be stronger than a mini Tesla and would be cheaper in the long run.
 
Ok, so, I understood, no it won't work, would only last a few minutes, and you'd kill yourself. Perhaps explained in a way a child would understand? And if voltage has no influence on it then what does?
 
I think I know what you want to do, but I'm not sure it it would be very practical. It's been a while since I've worked with Tesla coils, but I know they do produce an elctromagnetic field. I'm not sure ones so small would produce a very strong field though, not only that but you'd want to keep it facing up and away from your body, making the gap between you and your armor pieces very far apart. While it would be nice to have a switch to flip and turn off the magnetic field, I think your best bet would be rare earth magnets. They'd most likely be stronger than a mini Tesla and would be cheaper in the long run.

I think perhaps I'm being misunderstood. When I say "tesla coil" I don't mean it in 100% terms of the word. I'm using it to describe more of what a tesla coil does. There would be no gap in anything. I suppose the correct term would be inverter or converter? I'll draw up a design real quick and post it for you guys to see and then you can point out flaws and tell me if it would work or how I could get it to work. I have access to supplies at work so cost to me personally would actually be $0.
 
Don't know if this'll help but here is an extremely simple diagram. diagram.jpg
 
I'm not trying to be insulting, but from the looks of things, you don't understand electronics, high energy or electromagnetism enough that I'm really comfortable giving further advice beyond "don't". I also don't want to open the site up to potential legal issues.

The shortest possible version of my post is that this is a) much more dangerous than you realise, and b) not actually a practical - or even workable- design.

Stick with magnets or mechanical fasteners.
 
I understand what you’re trying to do and would like to caution against it. You would run the potential risk of electric shock if you perspire too much or are in the rain. At the same time, I completely understand you not wanting strapping for your armor.

As an alternative, I would like to suggest neodymium magnets. They are cheap, strong, and readily available. My wife uses 7.7lb magnets for her Mandalorian armor and it takes actual force to pull the plates off. Heck, washing it usually ends up with the vest stuck to the inside of the washing machine.

All you need to do is sew small pockets on the inside of your undersuit to shove a magnet inside of. Then, just put your armor piece (with its epoxied magnets installed) over the suit and SNAP it’s connected. If you use multiple points to secure it, you can even bend and reach in ways that may make one or two come undone without fear of losing your armor piece.

Heck, throw a couple more in the back and right thigh and you can potentially magnetically lock your pistol and rifle to your armor.

Here is a link to the kind I prefer to use for most of my work: Rare Earth Magnets N45 3/4 in x 1/10 in Neodymium Disk

They are 3/8” × 1/10” and have a pull force of 7.7 lbs. Definitely use a two-part epoxy to mount them to your armor and keep a good separator of cloth between them and whatever you mount in your undersuit. If you do foam armor, then cut a slit in the side of the foam and insert it inside the foam piece, reseal it with hot glue, and call it good.

As for the electronics, just mount a small battery pack inside the piece of armor for any lights. Make sure you wrap the battery pack in something to protect it from dampness. Not to sound crude, but an unlubricated condom with a twist tie around the wires works great for waterproofing a small battery pack (9-volt or EL wire battery pack). Then, just tape it up inside the piece and call it good.
 
You're right, I don't understand electronics, high energy, or electromagnetism, at least on the level that I'm asking about. But, that's why I'm asking. That's also why I asked for it to be explained in a way that a child could understand it, (because anyone who can do that has a far greater understanding of it than anyone else), and how I can get it to work. I'm a quick learner. And even if this diagram itself wouldn't work, eventually I could get it to do so. And no one should ever try what I'm going to do. But then again, no one should have created the atomic or nuclear bomb (two completely different bombs by the way). Hell, even though Nikola Tesla had a greater understanding of electricity than anyone, he still built the first electric motor from a dream that he had. Emphasis on the dream part. You can look it up. My point is that just because I don't have an understanding of it right this second doesn't mean that my idea is insane. It just means that it has kinks that need to be worked out. Kinks that will be worked out when I do have an understanding of it all. Also, not being insulting. Mean none of this as harmful in any way.

I'm not trying to be insulting, but from the looks of things, you don't understand electronics, high energy or electromagnetism enough that I'm really comfortable giving further advice beyond "don't". I also don't want to open the site up to potential legal issues.

The shortest possible version of my post is that this is a) much more dangerous than you realise, and b) not actually a practical - or even workable- design.

Stick with magnets or mechanical fasteners.
 
I understand what you’re trying to do and would like to caution against it. You would run the potential risk of electric shock if you perspire too much or are in the rain. At the same time, I completely understand you not wanting strapping for your armor.

As an alternative, I would like to suggest neodymium magnets. They are cheap, strong, and readily available. My wife uses 7.7lb magnets for her Mandalorian armor and it takes actual force to pull the plates off. Heck, washing it usually ends up with the vest stuck to the inside of the washing machine.

All you need to do is sew small pockets on the inside of your undersuit to shove a magnet inside of. Then, just put your armor piece (with its epoxied magnets installed) over the suit and SNAP it’s connected. If you use multiple points to secure it, you can even bend and reach in ways that may make one or two come undone without fear of losing your armor piece.

Heck, throw a couple more in the back and right thigh and you can potentially magnetically lock your pistol and rifle to your armor.

Here is a link to the kind I prefer to use for most of my work: Rare Earth Magnets N45 3/4 in x 1/10 in Neodymium Disk

They are 3/8” × 1/10” and have a pull force of 7.7 lbs. Definitely use a two-part epoxy to mount them to your armor and keep a good separator of cloth between them and whatever you mount in your undersuit. If you do foam armor, then cut a slit in the side of the foam and insert it inside the foam piece, reseal it with hot glue, and call it good.

As for the electronics, just mount a small battery pack inside the piece of armor for any lights. Make sure you wrap the battery pack in something to protect it from dampness. Not to sound crude, but an unlubricated condom with a twist tie around the wires works great for waterproofing a small battery pack (9-volt or EL wire battery pack). Then, just tape it up inside the piece and call it good.


HA! I actually looked at similar ones on Amazon. They were 6.6 or something though. Thanks for the tip! In the end, this is probably what I'll end up doing. I just thought it would be nice to be able to turn the magnets on and off, as well as not having any straps.
 
Ok, so tesla coil thing isn't needed at all I found out. Thanks to everyone for the tips. So here's what's up. If someone wanted to make attachable armor pieces without straps, didn't want to use rare earth magnets, wants the pieces to attach magnetically but also wants to be able to turn the magnets off then here's how it works. Turns out its the amount of coils around the piece you want to be magnetic that matters. For instance a horseshoe, you wrap a lot of coils around the center of it and attach the ends to a battery and the two ends of the horseshoe will give you a north and south pole. Turns out that the tesla coil itself was the kink in my design. Over thought it I guess. :p
 
Quick answer: nope

Why: you need electromagnets, and yes, I mean the good and efficient and expensive ones (20$-50$ a piece). And you would need the 20-50Watt pieces, depending on the part you want to mount.
So that would be at least 200 Watt/h of power with 10 armor pieces. A notebook battery got 50-70Wh, so you would need 4 just for one hour!
Or if you would use AA (they got 1,2V*2A=2,4Wh each battery). So 200Ah/2,4Ah=84!!!! 84 AA batteries each hour!

And I bet, you're not able to build a more efficient electromagnet then the companies, which earn money with it ;)

Just as a little hint, use screws! They are cheaper and don't need any power ;)
 
What about electro permanent magnets? http://en.wikipedia.org/wiki/Electropermanent_magnet This is the kind of set up used on magnetic security doors. It's essentially an electromagnet coupled with a permanent magnet. The permanent magnet holds your gear together unpowered, then you fire up the electromagnet briefly to negate the permanents field for separation.

They're using something similar to this on the Project Ara phones.
 
the prob is is a tesla coil is just a coil of wire that is shorting out so wont last more than a few mins at most
 
Truthfully this is a great idea, but it seems like your over engineering something that already has a simple and practical solution, because in reality when the batteries run low or a connection fails then basically you will have a pile of parts laying on the floor.
 
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