Instructables
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Electro Magnetic Spike Generator:

This is my EMP generator I designed and built using a cheap camera flash, £14 worth of 400V capacitors and some junk I had laying around. It demonstrates electro-magnetic induction by kicking an aluminium disk in the air. When the device is powered it charges 20 X 100uf capacitors to 400 V.

When this energy is released into a coil, a huge magnetic field is generated and induces a current in to the aluminuim disk. Now you might be thinking, "how will the disk be repelled if it is aluminium and is therefore not magentic". Well this current induced in the disk, creates an opposing magnetic field which boots it about 10 foot into the air.
  • This is enough current  to KILL YOU




This the old video:


yveg1 year ago
I would like to have a very small emp device. I am willing to pay for all the expenses.
Please let me if any of you can help.
Wizzup1 year ago
You should try using a thicker disc, I have a 3300uF 380V cap bank, about 240J, it shoots a 30g 5mm thick 60mm diameter aluminum disc at over 20m/s. My coil is totally flat, its 15 layers of 1.5mm thick magnet wire. It easily shoots the disc through a bit thicker cardboard.

I used a very thin disc at first too and then i tried the thicker one and noticed that it actually flies at the same speed as the thinner one, so the kinetic energy was multiplied by 5 by just using thicker projectile.
.Unknown.3 years ago
Is there an equation or something that you used to figure out that 750A flowed in the 10ms pulse? Could you tell me what it is?
eXtremeSomething (author)  .Unknown.2 years ago
After many wrong calculations the actual value for current is only: 40A
the current is voltage divided by resistance. when your capacitors have an inner resistance of 0,1 ohm the current will be I = 400V / 0,1 Ohm = 4000A. (caps can dump their energy at once and are just limited by the inner resistance.)
That would be true if this were a purely inductive circuit. Because the coil has inductance as does the capacitor bank, the pulse will be longer in duration and lower in current. Even though photoflash caps have lower ESR and ESL (equivalent series resistance and inductance respectively), the overall impedence of this circuit is probably in the tens of ohms. At 330v and 1 ohm, the current peaks at 330 amps. This still fails to take into account the reluctance lent to the circuit by the inductive coil which will further flatten the discharge curve. With that much energy, one would expect far higher launch heights, but the slow discharge of the electrolytic capacitors is the Achilles heel of this setup. I did a similar experiment but instead used 6 ~1uf 2,000-volt constant, 10,000-volt pulse rated microwave capacitors and a spark-gap trigger. At 5Kv, the 3.5" aluminum platter reached 35 feet, with only about 1/10 the energy input that this setup has. Please don't take this message wrong, this is still a much safer (in terms of voltages and peak energy levels) than mine, but if anyone wishes to replicate my results for greater impulse, feel free. (just BE CAREFUL! 5-10Kv is VERY nasty, especially when capacitors are involved)
eXtremeSomething (author)  Horstel-19802 years ago
I give up
eXtremeSomething (author)  .Unknown.3 years ago
(removed by author or community request)
I see, thanks.
Great instructable by the way
Hey! Nice instructable! How did you do the coil?
By the way: 20 X 100uF caps are 2000uf so the capbank has 0,5 x 0,002F x 400^2 = 160j = 160Ws
eXtremeSomething (author)  Horstel-19802 years ago
great scotts, MARTY! Yeah your right, I will now change it. To make the coil I twisted it around a 4" pipe and then held it in place with tape.
would realy hate to see this as a coil gun
eXtremeSomething (author)  dasimpson19813 years ago
Its funny you should say that. Ive made an addon that plugs into the output to make it a coil gun.
now that you should show a vid of what it can do i made one pure by accident was ment to be a pulse motor but insted fired the welding rods i was using at the core was copeing the cam flash would give it an extra kick it did to much lol
brendonl3 years ago
How did you charge the caps too 400v?
eXtremeSomething (author)  brendonl3 years ago
The camera flash circuit charges the capacitor bank up to 400V. Most disposable cameras have one but they only go up to 270 ~ 360 V. I used a proper hotshoe camera flash (external) as they are more powerful.
Clever thinking man! I wonder what would happen if you hooked it up to some external wires wrapped around the ferrite core of a flyback that might do some crazy s**t.
Did you use a camera flash or something?
that thing is skarry
rimar20003 years ago
Awesome! Congrats.
vishalapr3 years ago
This is realy cool! Well done!