Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Question about EMPs

  1. Aug 1, 2005 #1
    I have a question about EMPs
    now, i think i have made them before as i was experimenting with magents a while back (almost knocked out my calculator if i remember correctly, but what is the usuall way of making one? what determines how strong the feild is? how about how large it is?
    i amthinking of pulling a small prank on a friend of mine and a mini EMP would be perfect hehehe

    thanks for your help

    Last edited: Aug 1, 2005
  2. jcsd
  3. Aug 6, 2005 #2
    59 Views and no replies... Aww!!! Okay, the 'usual' way of creating an EMP is through a nuclear detonation. No fissile material? Okay, try using a flux compression generator. Again, you'd need explosives but doesn't have to be nuclear... Or a -very- time consuming way which hasn't been published because I made it up (LoL) is to rig a large coil which can disassemble itself through non-ionic means. EG Not using acid to dissolve the coil as this would short-circuit the system and no EMP, plus it has to be done in a fraction of a second.

    The EMP in any of the 'safe' types above is/would be created through a very large magnetic field having nowhere to go as an electromagnet is potentially stored current. If you suddenly break a circuit with a large magnetic field attached to it, you get a sparking effect which causes crackling on TVs, or a shock if you're stupid enough to be holding bare wires. This is caused, I think, by the magnetic field collapsing which means it's moving, which generates current, which slows the rate of collapse. In any case, if you do this along the entire coil in just more than an instant, the spark which effects TVs by inducing a small current in the wire 'stacks' into a large pulse. Well done, you've just created your first EMP.

    The trouble is, cheaply, a flux compression generator is still dangerous. You have to blow the coil, with attached high capacity capacitors to maximize field strength, in a sequence travelling along the coil. Each charge has to be powerful enough to almost vaporise the part of the coil it's destroying. Plus, as a prank? I mean, if it's his computer you want to effect, I don't think he'll see the funny side as it's rendered useless. It's kinda the equivilent of running car battery terminals through all the circuitry and the mess of the explosives around the corner's gonna turn some heads. And it's not gonna be focused, no, so it'd be a -lot- of computers, TV's... You get the idea.

    NB: A few assumptions are made here. Even if the theory behind it is wrong, the apparatus is correct. I just thought some reply is better than none for a topic as interesting as EMP's.
  4. Aug 8, 2005 #3
    hehehe well this should be fun attempting to make, yeah i guess as a prank it wouldnt work out too well hehe, ill probably wind up doing what i normally do, make it, then go into a feild somewhere with some electronics is dont need and see what happens hehe, quite the hobby i soppose

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?

Similar Discussions: Question about EMPs
  1. Question about EMP (Replies: 1)

  2. EMP effects? (Replies: 5)