
Parts
List R1 = 3K3, 5%
R2 = 1M, 5%
C1 = 0.1µF, monolythic capacitor
C2-C9 = 0.01µF 400 volt polyester capacitors
D1-D8 = 1N4007, 1KVolt diodes
Neon = Type NE-2 neon bulb
Q1 = MJE521 NPN power transistor
Q2 = MJE371 PNP power transistor
T1 = 1200:8 audio output transformer (green), Armaco AT-49
S1 = SPST momentary-contact, pushbutton switch
Additionally:
9-volt
battery clip, 10 x 5 x 2.5cm plastic case, 7.5 x 4cm perfboard or pcboard, two
8/32 x 1-1/4 bolts and nuts for electrodes, adhesive for mounting NE1, circuit
board standoffs (optional), hookup wire, solder,
etc.
Substitutes:
After several emails from readers I
have found direct possible replacements for Q1/Q2. If I come across suitable
others I will add them on a future occasion.
Q1: MJE521: The NTE184 or 2N5190
will work.
Q2: MJE371: The NTE185 or 2N5193 will work.
T1: Mode 60-282-0
(Audio) about $2.00, Armaco AT-49 (Audio) about $5.00, Hammond 141P (Audio)
about $19.00
I received numurous emails in regards to
the T1 audio output transformer. My answer: if you can't obtain this type or
similar either don't build the Dazer or find another type of transformer.
Period. End of discussion! I have not experimented with the 1000:8
type. Try it. No guarantees it will work. Why an audio output transformer? The
windings are much finer and the overal size of this transformer is much smaller
than the average power transformer. Compare it this way, holding a
mini-cellphone versus a stone brick.
WARNING:
THIS DEVICE IS NOT A TOY! We present it for
EDUCATIONAL and EXPERIMENTAL purposes ONLY. The circuit develops about 2000
volts at a respectable amperage. It can cause you pain and even damage if you
become careless and touch its output terminals. The unit can also damage
property as well so use it wisely. You should NEVER use the device on another
person! It may not be agains the law to possess such a device in your area, but
if you use it on someone you may be deemed liable a a civil and/or criminal
action suit. Don't just follow the golden rule after constructing the project,
instead just don't do it unto anyone. Included in the article are a number of
instructions on how to build, test, and operate the Dazer; all of them must be
followed to the letter. Do not deviate from the
procedure.
The Electronic Dazer is a modern, portable,
non-lethal-personal-protection appliance. It generates hight potential energy to
ward off vicious animals or other attackers. It is an aid to help exape from a
potentially dangerous situation. the device develops about 2,000 volts. Higher
voltages may be attained by adding aditional multiplier stages, but it should be
noted that those stage(s) will also increase the overal size of the unit.
The
Dazer is very compact, being built into a small plastic case. It is powered by a
single 9-volt battery, either NiCad or alkaline. (Editor's Note: the so-called
9-V NiCad actually provides only about 7.5V. Why? NiCad cells only give 1.25 per
cell. 6 cells in a 9volt battery gives it 7.5V and so the Alkaline type would be
a better choice).
The high voltage is applied to two electrodes which require
only light contact to be effective. When touched with the Dazer, the victim will
receive a stunning, but non-lethal jolt of electricity that will usually
discourage any further encounters.
The electronic Dazer is apower supply
which consists of a micro-size regenerative amplifier/oscillator coupled to an
energy multiplier section. It should not be confused with a cheap induction-type
cattle prods. The Dazer is more versatile than other high-voltage stun devices
currently being sold. Those devices are basically high-voltage, AC generators
which jam the nervous system. However, the Dazer may be used for heating and
burning applications, or anywhere a high voltage DC supply is
required.
(Tony's Note: Don't confuse the Dazer with a Stun-Gun.
The Dazer emits high voltage about 2000V DC, a Stun-Gun can generate VERY
High Voltages varying from 15,000V to 650,000VAC (as claimed by some
manufacturers), and can cause personal injury or even death. Stun-Guns are
considered banned illegal fire-arms, you risk criminal prosecution if law
enforcement finds one in your possession (Canada, not sure about
USA).
How it
Works:
Refering to the schematic diagram, the two power
transistors Q1 and Q2, form a regenerative amplifier operating as a power
oscillator. When Q1 turns on, Q2 turns on and that shorts the power supply
across the primary of T1. That current pulse induces a high voltage in the
secundary of T1. As C1 charges, Q1 turns on again and the cycle repeats itself.
Therefore, a rapid series of DC pulses are generated and stepped up by T1 to
approximately 300 volts at full battery charge. That voltage is rectified and
increased by the voltage muliplier section which consists of C2 and C9, and D1
to D8. The final output is approximately 2000 volts. The neon bulb NE1 is used
as a charge indicator and indicates that the unit is charge and operating
properly.

Check out
fig. 1 at the right; these are standard voltage doublers found in many data
books and others like the NTE or Electro Sonic catelogue. They can even be found
on the internet. Just do a search on one of the major search engines like Yahoo
or Google and search for 'voltage doubler' or
'HV'.
Construction:
As with all projects start out by laying
out and indentifying. If you do not wish to make a printed-circuit-board, then
you may use perf board as long as you remember to keep the leads of all
high-voltage components isolated. That is to prevent sparks from arcing across
your board. A 4 x 7.5 cm of perfboard is suitable for that purpose.
The first
components you should mount are the two transistors Q1, Q2, transformer T1,
resistor R1, and neon bulb NE1. Solder them in place (for PCB construction)
being sure that the transformer and transistors are hooked up correctly. Apply a
small amount of adhesive to the base of NE1 to hold it securely in
place.
Mount D1 to D8 and C2 to C9 on the board and make all solder
connections. Note proper polarity of the diodes. The off-board components are
next. Solder in leads for S1, and the output electrodes. Also solder in the
battery clip for B1.
Build the enclosure from some nonconductive material
such as ABS plastic. Drill holes for S1, NE1, and output electrodes. Be sure
that the output electrodes are about a cm or greater apart. Connect the output
wires tot the electrodes and insert them trhought holes from inside of the case.
Thread on the retaining nuts and tighten them securely. Set the circuit board in
the case and mount S1, securing with a nut. That completes the
construction.
Testing:
Before inserting the
battery and closing the case, a few test measurements should be made
to ensure correct operation.
With the ground clip connected to the battery
(do NOT connect the complete clip to the battery ONLY the ground), connect a volt or multimeter between
the positive clip and the positive terminal of the battery. Set the meter for
current reading, and press S1. You should measure a current of approximately 300
to 500mA. NE1 should be glowing.
With a high voltage multimeter or VOM, you
should measure about 2000 volts on the output terminals. Those measurements
indicate proper circuit operation. Let the unit run for about one minute (keep
pressing S1). Transistors Q1 and Q2 should be warm, but not hot to the touch
(BE CAREFUL!). Insert the battery in the holder and close the case. That
wraps up the Electronic Dazer.
Operation
and Use:
Activate the unit by pressing S1. NE1
will light indicating the dazer is fully charged and ready to use. Notice also
that only one pole of the neon light will glow, indicating DC voltage present.
It is important to remember that the device holds a charge even after S1 is off.
To discharge, (do not press S1) touch the electrodes to a metal object and note
the healthy spark discharge.
The Electronic Dazer was designed as a
self-defense weapon for use against vicious dogs or other attacking animals. The
device is most effective when the electrodes contact an area of low resistance
such as skin or flesh. Those include the snout or mouth since the resistance of
those areas are much lower than areas of hair or of fur. The electrodes could be
pointed to penetrate these areas better. The dazer generates great stopping
power. One contact will give a powerfull jolt and should discourage any further
attacks.
The device can burn and heat materials with low resistance. Those
include flesh, moistened paper or wood, etc. That makes the unit potentially
hazardous to humans. Remember, the dazer is not a toy but a quality
electrical appliance and therefore must be treated accordingly. Use the utmost discretion with this device!
Another
use for this device is as a high voltage DC power supply. It may be constructed
as avariable power supply if output taps are taken from various stages of the
voltage multiplier section. Remember, always disconnect the battery and fully
discharge the capacitors before working with the circuitry.
Note that if you
decide to 'Turbo-charge' your unit, select diodes which can handle that voltage.
This unit can easily be damaged (and stops working) by incorrect parts choice.
So be careful and watch yourself.
Copyright and
Credits:
The author and owner of the original project is Rick
Duker. Project was published in Hands-on Electronics 1987.
Again, this project is for educational and/or
laboratory purposes only and even so, it is your responsibility to check with
local, provincial, and federal law enforcement in regards to the legality for
having in possesion or the construction of this project. I take no
responsibility, whatsoever, for the use and/or experimentation with this circuit
and other lethal high voltage projects.
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Page Copyright © 2001 - Tony van
Roon