How stun guns work

How stun guns work

Stun guns are used by individuals for personal protection and by the police as non-lethal control devices. Stun guns do not kill but temporarily disable the attacker or perpetrator. A stun gun is far more effective than pepper spray to render the attacker defenseless.


The human body is one huge collection of nerves supplying the body with electrical impulses that make us move, feel, think, and sense the world around us. On a normal day, the nervous system communicates electrically using nerves and neurotransmitters.

If a muscle movement is required, a system of nerves communicates by neurotransmitters (chemicals) that jump from nerve to nerve until the signal from the brain reaches the target muscle telling that muscle to move. This communication can be interrupted and cause problems, such as in the case of a person who has epilepsy or multiple sclerosis because the nerves and neurotransmitters are damaged.

A muscle can be forced to contract by applying a mild external charge to a controlling nerve. Apply the charge and the muscle contracts. Electrical impulses are used in physical therapy for paralyzed individuals to exercise their muscles, which no longer respond to stimulus from the brain. If nerves receive a strong enough external electrical charge, they can be over stimulated and cause the neurotransmitters to react in an adverse manner.

So, what happens when a large jolt of electricity is applied to the body?


Stun guns have the power to deliver 100,000 to 300,000 volts and up to 3 amperes (amps) to the human body. The effect can range from causing a bit of pain to causing the person to collapse in a heap unable to move for up to 15 minutes. Even though the voltage sounds like it could cause death, it is actually harmless to the body and causes only temporary discomfort. The amperage of the charge is what controls the strength and 3 amps delivered by the gun is sufficient to cause temporary problems, but not harm.

The actual effect on the body is that the neurotransmitters are temporarily scrambled, making it difficult to perform their functions properly. The nerves affected most are the muscles. The internal organs and brain are not affected. The overall effect is dependent upon the size of the attacker, the voltage of the stun gun, and the amount of time the stun gun is applied.

If the stun gun has low voltage, the perpetrator is large, and the gun was only applied for a second, it may not disable the attacker. Usually, the stun gun must be applied for 2-3 seconds to have an effect. The idea is to stun the attacker enough to allow the victim to getaway. The good news is that it doesn’t matter where the stun gun is applied to the body, it will do the job. Nerves are everywhere on the body and the electrical charge affects them all.

Unfortunately, criminals can also use a stun gun. There are several instances where a stun gun was used to disable a victim for robbery. In England, stun guns were outlawed after a criminal disabled a policeman during an arrest. The criminal got away and the policeman was unable to get off the sidewalk for about 15 minutes.


A stun gun is actually a very simple piece of equipment similar to a transistor radio. A 9-volt battery powers the gun. The battery will send power to a circuit, which consists of several transformers (they move electricity from one place to another). The transformers increase the voltage within the electronic circuit. Then it goes to an oscillator, which provides a fluctuating current (think of AC or alternating current) to get the correct amperage (amperage is the unit of electrical charge or strength).

The electrical current goes to a capacitor, which collects and builds up a charge. The capacitor sends the current to a pair of electrodes and from there it goes into the attacker. The electrodes are purposely placed apart because they naturally want to complete the circuit by allowing the charge to go from one electrode to another. An electrical current needs a conductor and the human body is a great conductor. The stun gun should be placed so that both electrodes make contact with the body for the full effect.


A hand held stun gun is most commonly purchased for personal protection. It is small enough to fit in a handbag. The benefit to this style is the ability to conceal and carry it around. The problem with this type is that the victim must be able to have close physical contact with the attacker for 2-3 seconds to have any real effect.

A taser is a stun gun that has electrodes attached to wires and a gas-powered explosive charge. The trigger is pulled and the electrodes shoot out 15-20 feet and engage the attacker from a safe distance. Barbs built into the electrode help to fix them to the attacker and increase the probability of a direct hit. The problem is that the electrodes could miss the attacker and there is only one shot available.


In most states it is illegal for a private citizen to use a stun gun. Only the police are allowed to use them. If a private citizen uses a stun gun even for personal protection, they can be charged with a felony. Be sure to check the laws in your state before purchasing a stun gun.

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