A stun gun, also called a taser (Thomas A Swift's Electronic Rifle), is a non-lethal weapon used by police officers, army personnel, and by individuals, as a protection against personal attacks. They are not meant to do any permanent damage to a person, only to stun them temporarily.
Stun guns work by applying a high-voltage, but low-current electrical charge. Since the nervous system in our bodies works by sending electrical charges of its own through neural pathways, the electrical current provided by a stun gun "confuses" the nervous system. This can cause the recipient of a charge from a stun gun (the "recipient") to feel paralyzed for a brief instant, because his or her brain is now receiving mixed signals from the nervous system. Or, the electrical current can cause many random muscles to trigger, causing a spasm or convulsion in many areas of the body. The high voltage is needed to get the charge into the other person's body, and the current is kept at a low level (3 mA) so that the recipient will not be injured severely.
According to the makers of stun guns, a charge of 1/4 second will cause the recipient to feel intense pain and muscle contractions, startling most people greatly. 1 to 2 seconds will often cause the recipient to become dazed and drop to the ground, and over 3 seconds will usually completely disorient and drop an attacker, for at least several minutes and possibly for up to fifteen minutes.
The most common type of stun gun requires the user of the device to place metal electrodes directly in contact with the receipient. Some such devices are available disguised as other objects (such as an umbrella).
A longer-range version is the taser, in which the electrodes are connected to coils of wire and are propelled by a small gas charge (similar to an air rifle). This type of device has a range of approximately 6 metres (20 feet). They are used by some police forces. They have the disadvantage that they are single-shot weapons, taking a great deal of time to reload, though most are fitted with conventional electrodes and can therefore be used as a basic stun gun if necessary.
Prototype stun guns exist which replace the solid wire with a stream of conductive liquid (essentially salty water) which offers the range of a taser (or better) and the possibility of multiple shots. Others are experimenting with devices that use a laser to ionize the air between the user and recipient (thus making it conduct electricity), though such devices are currently much too large for a hand-carried weapon.
The "stun belt" is a device similar to a stun gun, but placed on the individual for some time and activated, when desired, by remote control. It is used in the United States as a means to control prisoners.
Stun guns are illegal or subject to legal restrictions on their availability and use in many jurisdictions.
The use of stun guns, particularly by law enforcement, is sometimes the subject of debate.
The use of stun belts, specifically, has been condemned by Amnesty International as torture, not only for the physical pain the devices cause but by what they view as the psychological torture they inflict on people wearing one. They have also raised extensive concerns about the use of other electro-shock devices in American prisons, as they can (and according to Amnesty, sometimes are) used to inflict cruel pain on individuals without leaving the telltale markings that a conventional beating might. The American Civil Liberties Union has also raised concerns about their abuse in prisons.
There have also been concerns raised about the risks that a stun gun poses to people with heart disease, and there have been reports of deaths of such individuals after stun gun use. The manufacturers recommend that the devices not be used on people known to have heart disease. It should be pointed out that alternatives to the use of stun guns also have substantial risks of their own.
Stun guns have been used at political protests such as those by the anti-globalization movement. Members of this movement have argued that the technology, and other "non-lethal" weapons, are likely to become tools for suppressing legitimate protest.
Electrical shocks have been used as an instrument of torture in many countries around the world.
External links:
Principles of operation
Effects
Variations
Legal restrictions
Controversy
