after a long and hard search for answers my research is concluded.
its to neccessarily a emp generator but it is a emi generator.
a single pulse of wid band electromagnetic interference will put most electronics out of its misery. will post an intructable on how to make a small unit capable of frying cellphones and crashing computers from 20 feet. it will be the size of a beef jerky packet from slim jim.

An EMP weapon requires explosives. I don't have a schematic, but the structure is co-axial: The core is a bar of hi-ex, say a metre long and 3cm diameter. Around this is a copper coil (uninsulated wire). The outer layer is an aluminium tube. construction ensures that the coil and the aluminium tube do not touch. Before detonation, there is already a current flowing through the coil, so there is already a reasonable magnetic field. The hi-ex is triggered at one end, so that the explosion travels down the device from one end to the other. The next few steps happen with a couple of milliseconds: As the explosion's wave-front expands, it pushes the coil into contact with the outer tube. This shorts out the coil, one turn at a time. As the explosion travels down the device, the magnetic field is rapidly "compressed" into fewer and fewer turns of the coil, until it eventually "bursts" out of the last few turns in a massively-amplified pulse. The pulse exits the device at light-speed, with enough energy to frag any unshielded electronics with a half-mile or so. Very shortly after, the explosion continues out of the device with all its usual force. UK security services went through a period of fear about these things - set one off in the back of a van in London, and billions of pounds of cash and shares would simply cease to exist, along with the collateral physical damage done by the actual explosion. Fortunately (?), it turns out that the engineering tolerances required to produce one make it hideously expensive (for non-national-military organisations), so it's far more likely that terrorists would use "ordinary" suicide bombers to cause damage, and hackers to wreck the computer systems.

A friend of my cousin had this thing in a big project box that when he pressed a button would interrupt phone calls, crash computers or make their screens go all stupid. it had a short range though, like maybe 20 feet? i cant remember much about it, but he said it was an EMP thing he and his friend had made in college. That was a few years ago, so I have no idea.

I was reading the responses and someone mentioned a marx generator. That person was close. The U.S. military uses a modified marx generator to simulate emp blast. what it is is a marx generator connected to a high power radio transmitter. You could in theory shrink the marx design down to fit in your hand and attach it to a simple tank circuit to acheive an "emp". All it does is transmit the energy from the capacitors into the victims laptop wirelessly.

i have a question, my professor will not stop useing the smartboard in my university, he said that if we could disable it with a small EMP he would give us an A for the semester and make the winner his student helper, every thing i have done so fare has blown up or just ended badly, how do i make a small enuff EMP to take out the electricity or power in the computer of the smartboard to take it offline or make it irresponsive for 2 or less Mins? must be laptop bag size or can fit in hand, i am 2 feet away from the smart borad, we are working on advanced science and electromagnetic forces. Dose any buddy have any sugestions?

http://www.dhbolton.com/articles/diy-emp-generator.htmlthis one is better:

You could probably create a small EMP with maybe 10 disposable camera capacitors wired in parallel

look at "electronic gadgets for the evil genius"

I'm assuming you're not looking for a simple EM Pulse. You get one anytime an Electromagnet is energized. You're looking for one large enough to do damage to computers and electronic devices in the vicinity. Correct? While I could theorize having past experience with a magnetizer that created those monster magnets in 12" hard drives, I think it would be irresponsible to help anyone design such a weapon.

http://www.amazing1.com/ Use to be in the early editions of pop sci & pop mech as a AD called "Scientific Unlimited" bought some laser diodes for a 100,000 lumen reusable flash grenade thing I had plans for in the early 80's worked too. (Need to remember not to blind the judges at a science contest) P.S. All you need is a large compacitor that can hold a charge large enough to be able to converted to a electromagnetic wavelength

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i thought u could make one out of the magnetron in a microwave but i have no idea if it would work or not

OOOOOO i understand how emps work now thanks to knoxaramathank you man. now since i understand how they work i can finnaly build one

I built a small emp with a disposable camera with flash. I made the coil with a 4cm plastic tube and 24awg copper wire coated with enamel (magnet wire). I wound 1 layer/winding about 3cm width of wire around the 4cm plastic tube. I placed a small digital 1$ watch on the coil and when I activated the emp, the watch would reset to 12:00. I tried it a few times and the watch always reset to 12:00 but wasn't damaged. I disconnected the coil and instead of the camera emp, I used a 100KV stun gun, about 1cm from both ends of the coil wire. There was a 1cm spark from both tips of the stun gun to both ends of the coil. After about 5 seconds the watch sitting on the coil was completely dead. So get a 100KV stun gun or stronger and try different types of coils to see which coil gives best result. A coil with a iron or ferrous core is supposed to give better results.

hello I am looking for a electronicmagnet puls generator to do the therapy from dr bob beck. I need 50 kilo gauss. saludos alex

You really can build one with just a huge capacitor bank charged up to lots of volts, then discharge it through a huge coil of a couple turns of huge wire. If you're lucky, the electricity will resonate through the coil and cause enough EM interference to fry sensitive components. Another design is exploding a small piece of wire, which sends out EM waves at the resonant frequency of the wire (double check that, I'm not sure). Check out http://amazing1.com/emp.htm.

defibrillator? i seen on a film, a hacker used the EMF between the 2 paddles to blank off his computers, apparently it really works and its got what you'v been saying about, not sure if theres enough joules i can be bothered to convert it to amps right now "a bank of capacitors to approximately 1000 Volts with an energy content of 100-200 Joules" just don't blame me if you play with one and get or do something nasty, or die, im only throwing in ideas

try on this site, picture on left side is schema of emp and you can buy parts there http://www.amazing1.com/emp.htm

I have a book on how to build one. (no explosives) it basicaly is an uber-powerful ellectromagnet that is powered by capacitors for a short but powerful bust of electricity. I'll post how to build it in with a cpl weeks. or you can just get the book "Electronics Gadgets for the Evil Genius"