Ultrapowerful Electroshock

[simply RED]

Here is the scheme of the most powerful electroshock device I was able to make.

Characteristics:
10 kV DC ; charging 30n ; 15-20Watts consumation ; running on 9-10V.

Schematics:
T1-T2 form a multivibrator that generates "sound" frequency (never measured it exactly, anyway it is less than 1 kHz)
T3 is an amplifier in "switch" regime. The diode in its base discharges the 33micro cap when T2 is open.
T4 is non phase reversive amplifier. The 110 ohms in its base adjusts the amperage in its collector chain (2-3A pulse).

The high voltage transformer is a coil from a car (used for fuel ignition).
D1:4 form a Gretc (how is his name spelled in English?) scheme and finally the capacitors are charged with the 10kV DC.

Anyone even with no background in electronics is able to make the scheme. The problem maybe finding the high voltage diodes and capacitors.
I used KC106G Soviet made diodes (2 in paralel !, 8 diodes for the cascade) and PTO - 10n ; 5% ; 7,5kV capacitors (2 or 3 in paralel).
(never been able to find better capacitors)

The first picture is the schematic plus some diodes and their pasport - the second is the completed device on a test table.

Note that high voltage is dangerous - this thing fries mice and will most possibly do the same to more sophisticated life forms :) . Do not touch either of the poluses even beeing it a DC!!! Work with protective gloves and plastic instruments to handle and test in the final phases.
(the best experiment is on a green leaf, the sound from discharges can be heared in the whole house and finally the leaf "burns")

[Jacks Complete]

Nice.

Getting a HV coil from a car might be quite a lot harder than getting the diodes and stuff, depending where you are. A scrap yard will have the HV part, it's the bit under the distributor cap. Diodes can be gotten from many places, but they all need to be rated to whatever the highest voltage in the scheme is, otherwise they will short or fry or both.

[sprocket]

These coils are actually probably the easiest part to get. They are called ignition coils and are sold at pretty much every car part store. They come in many different sizes and shapes, the larger are typically oil cooled. I've noticed no considerable difference in performance between large oil cooled ones and smaller air cooled. In fact the smaller air cooled are marketed as "high performance".

I've built a fairly simple 555-based driver circuit with variable frequency to power these coils according to the schematic found on this page: http://www.geocities.com/capecanaveral/lab/5322/coildrv.htm. It's hardly lethal, putting out about 1mA at 30kV, but it really hurts to get shocked by.

I also built a HV capacitor by wrapping the outside of a PP box with Al-foil and filling it with salt water. The foil is best used as ground and the salt water then becomes the HV side. According to my multimeter it has a capacitance of 0.9nF which isn't a lot, but it does make fat loud sparks when discharged.

[Chris The Great]

Just ask them for the coil, that is how I got one. But I overdrived it making 2 inch sparks and it died on me.

I'll try adapting this circuit to use the much smaller coil that comes in a lawn mower since I still have several of those. Old crappy lawn mowers are cheap to buy at garage sales or even cheaper at the dump!
And of course, assembling it to fit within a handheld device.


Your setup looks like a lot of my electronics projects there Red ;)
Thanks a lot for this circuit. I can put together some electronic stuff and understand it well, but designing circuits.... nope, I'm clueless!

[simply RED]

Success here lies in using switch regime amplifier (T3) with diode in its base (the n of the diode matches the p of the transistor). This way you have conductivity in both half-periods (after the 33 micro you have AC) without applying I(0) to T3. The first half period when T2 is closed - T3 is open - currency flows through - base of T3- charging the 33micro and through the 300 ohms. The second half period T2 is open. The 33micro discharges through the diode and T2 collector chain.

Device in action :

FLASH - arc passes through a green leaf (about 2cm).
Fl1 - arc travels 0,5 cm through the air (the green leaf is seen on the right of the electrodes).

In order to catch the flash I made small movies and then cut frames from them.

[Marvin]

Might be worth thinking about how things like Stun guns work.

They generally step up to an intermediate DC voltage set by the voltage of a really big electrolytic capacitor, then when you want to zap someone they dump this by a fast switching mechanism, like a thyratron or a big transistor into the primary of a second coil that steps up to 50Kv or so. The output of the second coil then goes outside the box directly.

Key things here,
Since the intermediate voltage is set according to the best capacitor available, you have a higher energy pulse for a given weight/size.
Secondly since the second transformer is fed in a single pulse the power is much higher.

[simply RED]

Schematics using intermediate DC need (at least) two times more elements than this direct solution (and is impossible to be made by a non-professionalist in electronics). The power at the end is about five times lower because the losses in the final coil (which needs to be special production and is not even available on the market) are very high.
The best device I've seen acc to the intermediate voltage scheme had stunning :) complex schematic plus special production final coil (homemade of course - everything on the market is pure crap) and the flash was like 2 mm wide. Here flash is 4-6 mm wide with about four times less elements.

Directly discharging capacitors into the victim was chosen - best solution after some years of experiments [see the pictures of the flash] :) .

(note - the higher the voltage - the more q (I=q/t) the capacitor gets, which means - even low capacity caps will be charged "well" if the voltage is high)

[Jacks Complete]

I've got to agree with simply RED on this. Fewer parts = cheaper and more reliable. Coils are a bugger for burning out, with the resultant arcing setting things on fire or leaving you with a dead device and a strange smell.

0.9nF isn't bad for a really high voltage capacitor, btw. It mostly depends on size, though, since you are limited by arc burn-through of the insulator material(s) and/or the oil/air gaps. Reading up on HV laser capacitors is interesting, I recall a few very smart designs. Using polythene as the dielectric is a great power booster, and thick tinfoil is a good conductor for it.

The easiest design I recall was a roll of foil and polythene in a plastic tube with oil for cooling.

Basically, buy some polythene on a roll, thin stuff, and the thickest foil you can get without crinkles in it. (Try to get the MSDS for the polythene, which should tell you the thickness, and you can look up the dielectric strength and calculate the expected breakdown voltage for two layers.) Now take your clean work surface, and unroll the foil. You want a long length of it flat on the table. Now take your polythene, and overlay it. You need at least an inch both ends and sides to stop arcing around the insulator. Now repeat twice more. This ensures no thin spots blow your cap. Next add the other sheet of foil. Avoid any metal bits on anything, and ensure the edges are as smooth as you can get them. You might want to fold them over or something, rather than cut them to size. Now, wrap one layer of the three layers of plastic over the edge of the foil on both long sides. (That step is optional)

Add two tabs for your discharge. One either end on the same side, keep them fat and thick, and multi-stranded copper is better than bar, and more strands is better, and spread the ends out so that the discharge isn't coming through one tiny bit of foil. Solder these on well. You will need flux to get rid of the aluminium oxide that will otherwise insulate it. Smooth the solder off. You might need to insulate one or both leads, too.

Now, carefully roll up your capacitor. Roll it as tight as you can. Keep it tight with a zip tie or three, and then put it in a plastic tube with a sealed end cap or some kind of container that will not melt from oil.

Add some oil to a bit over the top of the roll, and there you go! You will be able to run this to pretty high voltages (1kV+, you worked it out beforehand) mostly depending on the thickness of your plastic. Before you charge it right up, though, you want to get some of the air out of it. Hook it to an AC source and let it vibrate for a bit, and the oil level will drop as the air bubbles out. Top up the oil. Have fun!

Look on laser websites for this design plus pictures. I've also seen bawls glass bottles used for a capacitor array. (Glass is a very, very good dieletric, but seriously fragile and heavy!) There's lots of stuff out there. Just remember to use a small resistance to stop yourself getting shocked before handling.

[zajcek01]

The car coil is very easy to get, but I personaly like better the TV Flyback transformer with uilt in cascade. The switching circuit is made of 555 chip and MOSFET transistor to switch the current. Transistor needs to be cooled. Then you simply add the capacitor in paralell with the coils output to get the higher current.

I had a shock from that kind of appliance and it threw me across the room under the chair and I woke up cupple of minutes later not remembering exactly what has happened. :D

ps. sorry for my english

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[electricdetonator]

Seems the issue is split all over the place here ;)

Just replied to the cattleprod thread with a ASCII schematics for a stungun using a cascade and neon transformer.

But what I'm always missing are the protecting diodes short circuit the inductive parts like the car coils ?

Or do they have build in protection ?

BTW high voltage caps are within every flash light, even in disposable cameras ;)

And with a cascade with 6 400 Volt caps u can reach 1,2 kV, make them 12 and you've doubled the fun ;)

High voltage diodes and caps can also be found easily in old TVs and monitors.
But be sure you discharge them before handling !

[Jacks Complete]

a 1.2kV cascade isn't easy. You will have to rate all the components in the cascade to the highest voltage found, else it will arc over. This becomes an issue as big diodes cost a lot more, and high voltage caps of a desent breakdown voltage are expensive. Buying 12 stages worth will cost a lot!

[electricdetonator]

a 1.2kV cascade isn't easy. You will have to rate all the components in the cascade to the highest voltage found, else it will arc over. This becomes an issue as big diodes cost a lot more, and high voltage caps of a desent breakdown voltage are expensive. Buying 12 stages worth will cost a lot!
Then main advantage of a Villard cascade is that you'll only need caps and diodes with 2x input voltage, to gain Nx ouput voltage ;)
See e.g. here:
'http://en.wikipedia.org/wiki/Voltage_multiplier'
'http://www.kronjaeger.com/hv/hv/src/mul/'
And just look here for "Hochspannung" 'http://www.fingers-welt.de/gallerie/eigen/elektro/subversiv/subversiv.htm'
With 22 caps and diodes it'll multiply the 90 Volt coming from the self made transformer to 22 x 90 V = 1980 Volt and instead of the used 3 kV caps 200 Volt caps should be enough ;)
A nice extra is the last high voltage cap with 10 kV and 10nF ;)
And high voltage caps aren't so expensive, see e.g. here (again german, sorry):
'http://www.oppermann-electronic.de/html/keram__hv_c_s.html'
100 1 nF 1 kV caps for 6,54 Euro
1 10 nF 15 kV cap for 8,50 Euro
100 1 kV 1,4 A diodes for 7,67 Euro
But you are right it's not very useful to make a cascade more then ten stages when you want to have current at the end.
The usual way to gain higher outputs with less parts is to use a second stage transformer driven by a spark gap / cap resonator.
Something like this:
'http://www.fingers-welt.de/gallerie/eigen/tonne/grille/zuend.pdf'
HV is really fascinating ;)

[lamazoid]

First of all, hello there!

I'd like to present my work - the result of more than 3 years of stun guns development. This is really powerful one, circuitry based on taser concept, and it causes any person to fall down immediately, unlike common commercial stun guns, where it takes 5 more seconds for effect to come. Another goal of this project was simplicity and kitchen-based technology, so (i believe ;-) anyone will be able to make it even without electronic experience.
Here is the link:
http://steelrats.net/readarticle.php?article_id=119

[evilgecko]

Microwaves are very handy for high voltage components. Buy the broken ones for cheap ($1) of online auction site. Each microweave has one 1800-2000V 1uF capacitor and a 2500V diode in it. The transformers are worth keeping too although are not suitable for your project.