Can you help me with my mini E.M.P. generator design?

Hello everyone!

I am new here so tell me if I have broken any rules :)

I am currently planning on bulding a handheld E.M.P. generator (it's dangerous, I know, sorry) that is capable of killing a small devices (e.g. a small camera) at close range (<10cm). I got to the capacitor bank and wondered if 180J is enough for my needs? I also have some other questions (in no particular order):
- What is the bare minimum to kill such devices?
- Does it normally take 90 secs to charge a 90uF bank to 2kV (using a DC boost converter)? I have never designed a high voltage charging circuit before so I don't really know if I'm doing things right.
- Is my capacitor configuration good enough or does it need tweaking (e.g. more voltage)?
- How do I protect my circuitry from getting blasted by the coil?
- Is a single pulse sufficient?
- What kind of switch should I use for high voltage?
- Should I use lithium-ion batteries for supplying power?
- Should I make the frame of the device out of metal?
- Should I be using a DC boost converter for charging capacitors? If not, suggestion?
- Should my coil have a little or a lot of inductance?

Again, I am fully aware this has "Darwin Award" written all over, sorry about that, but I think this is safer than guessing around.

Thank you for reading this! Looking forward to your responds!

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iceng2 years ago


Low Inductance, LOW Resistance for short, high current, directional pulse is best.

are mostly diodes, EMP induces currents into PCB traces which act as
antennas and damages the week PN junctions which may short or burn open.

Turning the appliance Off does not protect it from an EMP.

Either way they (damaged diodes) wont ever work again.

I don't know how to make a directional EMP style coil. That's why I'm still alive.

mr.derpinton (author)  iceng2 years ago

So how much inductance is low enough(ball park figure)? Does that also mean I should use air core (or plastic for manageability) instead of steel (cannot find pure iron)? Should I also re-arrange my caps to maximise the voltage (4kV sounds hard to manage safely)?
Is there any kind of metal shield I can put around my circuitry to prevent the coil from burning it? Like an sealed box lined with aluminium foil?

Thank you!

iceng2 years ago

This heavy iron switch separated by mylar was used to discharge a locked basement vault full of 3 foot tall 60KV capacitors in an IIT flux compression experiments.

Slam SW2.bmp
iceng2 years ago

Use wood and or plastic.

Charge at leisure, disconnect and fire coil with Stud or Hockey Puck SCR which can

handle 20X spec current once every ten minutes. Never Use a Triac !

mr.derpinton (author)  iceng2 years ago

Thanks but the part list is a bit out of my reach. I want to keep things as simple and affordable as I can because I am a̶ ̶c̶h̶e̶a̶p̶ ̶m̶o̶t̶h̶e̶r̶f don't have much money for the whole project and they don't sell specialised parts over here.

You mentioned "Use wood and or plastic". Does that I mean should make my frame out of PVC pipes (the most practical kind of plastic I can think of)?

Thanks in advance!

Don't bother to make something if you know it will not work.

Asking the same questions over and over will not change the answer.

The power SCR is your only hand option.

Make it out of anything that is strongly non-magnetic.

mr.derpinton (author)  iceng2 years ago

One more question: Can I use a moving switch such as a solenoid to move metal contacts?

Metal contacts will NOT Work they bounce.

iceng iceng2 years ago

Even a sealed mercury whetted contact relay or a power mercury displacement switch will not produce the speed you need for the EM pulse.

iceng2 years ago

You want a directed CNAIR device.

empBox.jpgEMP Flux_compression_generator.pngFLUeXplode.jpg
mr.derpinton (author)  iceng2 years ago

Can you please elaborate? Am I going in the right direction? Thanks for your respond!

Basically, it's a solenoid with an explosive core, encased in a metal tube, but the coil does not touch the tube (1st diagram).

The device is switched on, and the solenoid generates a magnetic field.

When the explosives are triggered, they are detonated from one end, and the explosion travels along the core (2nd diagram). In that fraction of a second, each turn of the coil touches the metal tube in turn, and is shorted out - this compresses the magnetic field, rapidly, towards the antenna end of the device, which emits an EMP just as the explosion reaches the end of the tube.

It's a one-use device, not hard for a hobbyist to build with current technologies, and the use of one that would fit in a van could disable an entire financial district. So, please, don't tell anybody how to build one...

mr.derpinton (author)  Kiteman2 years ago

I cannot use explosives here :( I'm not that mad. Thanks for explaining, though!

Basically, an EMP is a magnetic field that either forms or collapses very quickly.

For legality's sake, your original idea is probably your best, though it would probably only work at almost touching ranges. For the circuitry, look at coil guns and can-crushers, then ramp up the capacitance as much as you dare/are able. Make sure, though, your coil can carry large loads.

mr.derpinton (author)  Kiteman2 years ago

Thank you but can you tell me how much energy (in Joules) I should make it store (a vague baseline)? I don't want to spend my money on a cap bank and later to realise that it doesn't really work.

Sorry, no.

Your best bet is to look at the coil-gun projects and work from there:

Good luck with it. Don't get caught trying to use such a device on anything you don't own. Most countries have regulations against such devices that come with some stiff penalties.

mr.derpinton (author)  mpilchfamily2 years ago

Don't worry, I will not get caught :D

Kiteman2 years ago

No rules broken (although you may kill a few devices in your researches), but you might find a better response to a request like this if you post it as a forum topic (more views, and more likely to get a conversation going).

mr.derpinton (author)  Kiteman2 years ago

Thanks for your tips. I was hesitant as most forums consider this device a taboo.