Updated "Dec 4 2007"
The low powered version is probably still around 50,000 volts
on a slower pulse rate.  
The main power limitation to this device is T1. It is actually a minature
audio transformer connected in reverse to step up the 12 volts to around 400 volts, with no load. But this is not an
ideal part for this purpose as it doesn't have the ability to produce the high currents
that would result in a more sustained spark on the output.
This Medium powered version has a center tapped primary with dual transistors,
resulting in a more efficient circuit. For Simplicity and "Off the Shelf", this was
the best I could do.
If your an adventurist, you could wind a small transformer for any of these units below.
This would allow for higher efficiency and more current draw.
On the "Low Power" Stun-gun, Current draw is about 80 Ma at 9 volts.
On the "More Power" Stun-gun, Current draw is about 225 Ma at 9 volts.
With dual batteries, Better yet, 6 to 8 "AA" cells
In No Way Do I Recommend Building these Stun-Guns or the actual use of them for any purpose what so-ever.
I Assume NO LIALIBITY for any resulting actions of those persons who build or use any of these devices!
A Real Misconception about Stun-Guns, Is the Voltages.
Although this Sound Good in the Advertizements, It is Current that does the damage and any spark capable
of pentrating through the clothing and skin is totally sufficant to do the job.
A blue spark looks pretty and will hurt, but a "YELLOW SPARK" is much higher current and REALLY DANGEROUS.
The "Flash-over Voltage" of this Insulator is 80,000 Volts and that is over a "surface distance" of about  11 inches.
When have you ever seen a 100 KV Stun Gun with even a 10 inch Spark Gap?
In Reality, the spark gap determines the "Actual Voltage Available at the
probes".
With a spark gap of 1 to 2 inches or so, it is No-where near the 100,000 to
750,000 volts that these manufacturers make claims of.
NOTE:   In most countries throughout the world, It is "Illegal" to "Make",
and/or "Possess", and/or "Use" this device
SO CHECK OUT YOUR LAWS AND PLAY CAREFULLY
As to Parts, For those wishing to Just Experiment:
However, In No WAY will I supply a Bobbin for this, or make this transformer for Anyone.
I can supply the Small Transformer for Either one of these Circuit.
I can Also Supply the Fair-Rite Core #4077375411
I Can Also supply the rest of the parts,
Don't Even Ask!
Also Note:
In Order to make this Output Transformer so it will work without Shorting Internally,
It Requires it be Vacuum Potted in Epoxy Resin or Other GOOD Insulating Materials.
Simple "Low Power" Stun-gun Schematic, 1
"More Power" Stun-gun Schematic, 2
A Commerical Made Stun Gun.
Here is an Inside View.
The little "X" CROSS of Metal that appears on the Circuit Board,
is a Cheap way to replace the small SCR Timing Circuit that I use in my Designs.
Its a Small Spark Gap, but is not easy to adjust properly and definately Not very reliable.
The Output Spark gap is 15/16" and the Human Contact Probes are spaced 2 inches apart.
This unit is Faulty, (Bad Transformers) But I would estimate the output was about 50KV.
All Imformation in this Article is "Copyright protected".
Chemelec
*Copyright © 2007*