posted January 16, 2000 03:10 AM            

that transformer dr-d sounds more like a neon sign transformer if it's big... fluorescent ballasts are usually a foot long and a few inches by a few inches... they have to be fairly small to fit into the ceiling panels that house the lights. some neon size transformers (smaller ones) may also be this same size but most are larger depending on how much lighting they have to run.

where did you happen to come by this transformer? it almost sounds like a microwave oven transformer which wouldn't do you much good either except to kill yourself. the two wires... do they come out of the same side of the thing? if there are only two then one would be in, one would be out and the case would have to be a common ground.

oh and the comment about audio transformers... they would not be good for a high voltage application, they are usually impedance matching transformers which don't really give you good winding ratios for high voltage. the easiest to come by high voltage transformers are in old tv's and auto ignition coils.

l8r...

posted January 25, 2000 06:51 PM         

I am seriously considering building the transformer on my own since getting a good one costs money (car ignition coil). I have thought of several compact methods, not sure how well they would perform. I have plenty of magnet wire in my electronics box. Any one know of a place where I could find good info on winding my own or any personal experinces?

posted January 28, 2000 04:48 PM         

I'll keep the TV transformer in mind, I'll try to find some shops/junkyards.

posted February 01, 2000 06:04 PM         

I have not had time to go through all of the information there to find out what parts (tv,micro,oilheater,etc) are the best suited, cheapest, and most readily avalible for stun gun transformer coils.

It looks like though building a compact stun gun like the commercial models isn't that all easy. If my gun ends up being big, I will design it to where it is most compact and easy of use possible. Most of these transformers are very big and bulky. Maybe commercial stun gun's use voltage multiplier cascades to mainly increase the voltage? I am still looking into this and what is the most cost effective and easiest obtainable parts for my gun.
http://www.geocities.com/CapeCanaveral/Lab/5322/hv2.html http://www.mathematik.uni-marburg.de/~kronjaeg/hv/

On a side note, UBB edit feature totaly fucks up the links, I've had to edit this about 5 times now. A bug they could(should) fix easily.

posted February 01, 2000 07:25 PM            

a note on transformers:
flybacks work good for small things
so do car coils
oilheater starters are kinda large
so are neon sign transformers
mots (microwave oven transformers) are no goood for much of anything high voltage related unless you get ten hooked together in which case you are seriously asking to kill yourself

the first link on the first page you posted is the design i used for the project i built. also a note about posting url's... always put an extra enter or two in front of them and it doesn't get so mucked up.

if you need to find the coil on a car look for the high voltage wires that go to the spark plugs and follow them to the distributer (round thing about the size of your hand). the wires from the spark plugs all go into the distributer and the middle wire coming out of the distributer will eventually lead you to the coil, usually about the size of a glass or coke can or something that size.

good luck on the project...

posted February 01, 2000 08:22 PM         

I will probably end up using a car ignition coil as T2 and a smaller transformer as T1 in the circuit. I need to also figure out that rather large ~(4" long, 3" wide, 2" deep) transformer I have and see if it is of any use.
Microwave oven transformers would work if the primary was re-wound, or am I wrong on this? I think I saw this discussed on some page...
I will do my best to find some old TV's and visit some surplus/salvage stores to find some flyback's, but I doubt my succes. If all else fails it will be the above setup I wrote about.

About the URL's, I actualy put 3 CRLF's in front of them but UBB kept stripping them out. grrr (@&#$(@

When I have this project finished and I am satisfied I will write up a schematic, parts list, how to get parts, and basicly step by step construction of the whole device and post it on a site.

posted February 05, 2000 11:03 PM            

a note on this transformer deal... always remember that what you put in in terms of power is what you get out. voltage/current ratios change but power stays the same. running the same circuit with a standard ninevolt will NOT give you the same results as a large lantern battery of about the same voltage since you can get more power out of a bigger battery.

also i personally have only seen a few car coils and i didn't think they were too big or bulky. tv transformers probably do put out higher voltage though.

posted February 06, 2000 01:44 PM         

I plan to step up the voltage considerably before it goes to the ignition coil. Hell, if I can find another car to rip out the ignition coil I could use 2 and get almost 100kv?

1. About bulkyness, since this of course won't be a handheld unit, my friend suggested a cattleprod like design. I have the design made out, it will totatly be encased in PVC. Very good looking design.

2. About batteries, wont a car battery have too much current and kill someone? Ok, back to my model, I will experiment with different batteries, but here is some questions if anyone feels like answering..

What would be most effective in terms of voltage/rapid frequency? Or what about battery life? 2x9v=18v, 2x9v=9v2xcurrent, 2 or more D cells?, latern battery?

Of course series for more voltage, and paralell for longer battery life. But you won't be holding this thing on for minutes on end...

posted February 06, 2000 03:59 PM            

also hooking up two transformers together... i'm not sure how well that would work since there would be losses in transferring power from one transformer to the next (input and output impedance losses). i have always kinda wondered about that but never done it... i have about four or five old flyback transformers laying around that i never got around to using... maybe i will try that sometime.

as far as batteries and frequency... a two transistor / two resistor circuit will oscillate at a fixed frequency which does not necessarily give the best frequency response of the transformer. ie lower output voltage since the input frequency and the transformer frequency aren't "tuned" to each other. getting a circuit working that was tuned to the right frequency would be a little tricky though cause you'd first have to figure out what frequency it was for each particular transformer and then design your input circuit around that to generate the right frequency.

as far as batteries... like for the circuit i have it will run off 12 to 15 volts so it is a lot better to have better current handling capability from the batteries (parallel batteries) than to have higher voltage. the idea behind battery optimization is to have the most available output power right when you need it (not over a long period of time). usually that power is proportional to battery size and how much current you can draw. for instance if you had two lantern batteries capale of handling 3 amps per battery and you hook them up in parallel, you get power capability of 3amps x 2batteries = 6 amps total. power = volts x amps = 6 x 6 = 36 watts. now say you have a nine volt capable of 1amp output and you take two of them. either way you hook them up you only get half the power of the other arrangement. in parallel you get 1amp x 2batteries = 2amps total. power = volts x amps = 9 x 2 = 18 watts. in series you get 9volts x 2batteries = 18 volts total. power = volts x amps = 18 x 1 = 18 watts. so really what you want is something with good current capability which is usually directly related to how big the battery is. a car battery for instance can have up to 800 or 900 crank amps which would be really ideal i seriously doubt your circuit would use that much power (i seriously HOPE it wouldn't) but on the other hand, not having a big enough battery means it cannot drive the circuit at it's full capability.

anyway have fun. i like the pvc idea.

posted February 06, 2000 04:38 PM         

Dual ignition coils, 60kv. 2 of the same type is optimal of course. I'll experiment with this if I can get a 2nd one. Else, it will be the biggest trans + ignition coil.

What is the maxium amps you can get away with without frying someone with high voltage and killing them? The idea is low current high voltage after all.

A lantern batery is pretty good but big. Not sure what I will use. I also have some 12volt rechargeble batteries from florecent light backup things. They replace both when one goes bad, so my dad got me one one time. They are roughly the size of a lantern battery. I could make an optional external power plug/port to plug those batteries into the side via a cable. Rechargable = lots of zapping fun.

posted February 09, 2000 07:09 PM         

I am ready to start building this thing. My question is, What is the best method for making pulsed DC? Simple transitors, or transistors w/poteinometer for tuning, or a 555?

555 is out of the question for now since I'm not yet fammiliar with them. I would like to get the maximum effeciency out of the thing by getting the right or close to the right frequency of the coil. Of course my design allows me to unscrew the pvc case and take out the parts for re-building/upgrading if nessasary. (I plan on making this gun, and then a smaller almost handheld unit which I will take time to make most efficeint, and might go back and modify my original one if need be. This allows me to compare the results of 2 diffrent setups side by side.)

*** My thoughts, 555 would be most exact for frequency, but since it is unknown for each coil and there is no general frequency (maybe there is, but I have not heard of one.) to go by tuning it would take lots of time.
*** Fixed transistors would not get it right unless it was calculated and the coil freq was known.
*** transistors with a ponteinometer allows changing of the frequency with a mear twist of a dial. Seems like the way to go for circuits using an unknown freq coil.

posted February 10, 2000 05:43 AM            

This page, http://www.eskimo.com/~billb/emotor/emotor.html , has links that go on to other pages with more links, all on high voltage devices that are home built.

It seems everyone here is thinking only about portable shockers. What about a stationary generator that would protect an area of a house or property? A fixed site generator could be much more powerful (lethal if desired).

Imagine this: An intruder breaks into an empty house. He knows no one is home 'cause he watched you leave. He steps through a doorway leading to a darkened room when ZZZZTTT! A blue flash of light and the stink of burnt flesh. He falls dead to the floor.

He didn't know that there where metal stips running from floor to ceiling on opposite sides of the door frame with a 250.000 volt potential built up. When he stepped between the plates, the voltage discharged through his body, stopping his heart, and his crime, dead in it's tracks.

Perfect home defense. No noise or ballistics. Just drag the body out and dump it somewhere.

An automotive spark transformer attached to a giant capacitor with the poles attached to opposing plates in the door frame might do the trick. A 12v adapter hooked up to the house power keeps it charged and a pressure switch under the doorway completes a circuit that allows the charge built up in the capacitor to discharge into the transformer where the current is stepped up enough to jump the gap.

You want just less than the voltage needed to jump across the gap of the doorway so that anything conductive moving through will discharge the capacitor.

If that wouldn't work, another thing to try would be hair fine wires hanging in a hallway or doorway. Tiny lead fishing weights at the ends keep the wires from swaying. A metal plate is hidden under the carpeting and the wires carry the high voltage to the plate through the body of an intruder who contacts them.

Neat thing about electricity is that it will go through body armor too since it's only fabric and has no insulation value. Good for SQUAT teams.

posted February 10, 2000 04:36 PM            

dr-d 555 circuits are extremely simple to build if you can build anything with chips like on a breadboard then it is a simple step to soldering it up. i have a computer program that will calculate frequency and all that stuff so you don't even have to think about it and it will show you how to wire the thing up. parts you can get at radioshack or order online of course. the transistor circuit (an astable multivibrator) is really easy to do and i have diagrams for it but don't have the time to post them right now... email me if you want any of this stuff.

nbk2000... your little intruder idea... need i say that it is just a tad dangerous?? talk about asking for a burned down house or facility. now of course if you are DESIGNING somethin, like a new protected bunker with a concrete hallway you would have to walk through to get to the protected area... that would definitely be cool. a swat team would walk halfway down the hallway (hanging wires turned off) wondering what they were when all of a sudden, sprinkler system trips on for a few seconds then the electricity trips on. and just as soon as it came on, poof, everything turns off with a pile of unconscious people on the floor.

posted February 12, 2000 12:39 AM            

i picked up a 15kV 30mA neon sign transformer today... i have some nice little coat hangers on it doing the jacob's ladder thing... pretty cool. i would definitely not recommend this type of transformer for any kind of people or animal zapper though... definitely too big and heavy.

posted February 13, 2000 01:44 PM         

From experimentaion, it seems that the coils will spark from no matter what polarity I hook them up. Odd. I also didn't see any change in voltage when using 2 together, but i will retest that once i get pulsing dc going through it.

Today I plan to make a simple 2 or 3 transistor inverter circuit.

m3nth, please email the transistor circuits for now as soon as possible. citadel@mindless.com

posted February 18, 2000 03:12 PM            

To Dr-D, you can download the 555 data sheet from www.national.com, they are very easy to use if you get the right circuit. If you set it up to produce a square wave, this is ideal for any HV circuits based on back EMF as the switch from +v to -v is very fast.

BTW, does anyone in the UK or Europe have any HV caps for sale? If you do please let me know, it's for a good cause ;-)