Fears over Taser gun expansion

[Xaccers]

Originally Posted by Flange

Normal skin resistance is usually greater than 300,000 Ohms.

The barbs penetrate the skin though.

And even so, at 300KOhms, that's still 167mA!

[danielf]

Originally Posted by Xaccers

You need approx 100mA across your heart to stop it (look up the case of the US Navy electrician who killed himself with a 9v multimeter)

I just did. The crucial difference seems to be that he took one probe in each hand (and penetrated the skin). This means that the current would have passed (internally) from one hand to the other, passing through the heart on its way. If you break skin with a taser the current will take the shortest route between the prongs. The current may well exceed the 100mA needed to stop your heart, but it won't pass through the heart as it is extremely unlikely that it will be located on the shortest route. In fact, you'd probably have to taser the heart directly to get that effect.

Rule #1 when playing with currents. Don't ever hold a live wire with one hand whilst holding on to grounding with the other hand.

[Xaccers]

Ok, that was my thinking too, so bummer if they spread apart/deflected sufficiently then!

[danielf]

Originally Posted by Xaccers

Ok, that was my thinking too, so bummer if they spread apart/deflected sufficiently then!

I'm not sure how tasers work actually. They fire little 'darts' that are connected to the taser and the current runs between the darts presumably?

Edit:

Wiki

Modern taser-type weapons fire small dart-like electrodes with attached metal wires that connect to the gun, propelled by small gas charges similar to some air rifle propellants. The maximum range is up to 10 meters (30 feet). Earlier models of Taser needed the dart-like electrodes to embed in the skin and superficial muscle tissues layers; newer versions of the projectiles use a shaped pulse / arc of electricity which disrupt nerve and muscle function without needing the metal prongs on the projectile to penetrate the skin. Early models had difficulty in penetrating thick clothing, but the 'pulse' models are designed to bring down a subject wearing up to a Level III body armor vest.

[jkat]

http://uk.news.yahoo.com/skynews/200...45dbed5_1.html

A policeman has accidentally shot himself in the leg in London

so we are going to trust em with tazers as well??

[TheNorm]

The Taser seems to work on a variety of levels, including neuromuscular incapacitation and shaped-pulse technology. More from the Taser website can be found here: http://www.taser.com/research/techno...s/default.aspx

[Sirius]

Originally Posted by jkat

http://uk.news.yahoo.com/skynews/200...45dbed5_1.html

so we are going to trust em with tasers as well??

You would be surprised how many times someone has a ND ( Negligent Discharge) in the force's and we give them far bigger weapons than a taser

Originally Posted by jkat

http://uk.news.yahoo.com/skynews/200...45dbed5_1.html

so we are going to trust em with tazers as well??

Well, it mitigates the effect of negligent discharge .

But, to be serious , negligent discharges happen - in the forces, it happens, in the police, it happens; guns, bullets, humans, forget the safety catch, have one in the breech - negligence happens. It doesn't mean we should ban armed police because one shoots himself; that would be like banning traffic cops because one speeds.

Could have been worse - could have hit a civvy passing by.

[Sirius]

Originally Posted by foreverwar

Well, it mitigates the effect of negligent discharge .

But, to be serious , negligent discharges happen - in the forces, it happens, in the police, it happens; guns, bullets, humans, forget the safety catch, have one in the breech - negligence happens. It doesn't mean we should ban armed police because one shoots himself; that would be like banning traffic cops because one speeds.

Could have been worse - could have hit a civvy passing by.

I still say "Give them the Goddam taser's NOW"

Originally Posted by Muggle

I still say "Give them the Goddam taser's NOW"

I bet the lad who got put in the bin (and was put through the mental anguish of looking like a idiot - if it walks like a duck, looks like a duck, and sounds like a duck, it's probably a ......) wouldn't have been so lippy if the copper had been carrying a taser.....

[danielf]

Originally Posted by foreverwar

<snip>

Could have been worse - could have hit a civvy passing by.

Or worse even, he could have shot himself in the foot.

I'll get get my coat.

[Escapee]

Originally Posted by Xaccers

The barbs penetrate the skin though.

And even so, at 300KOhms, that's still 167mA!

I'm guessing that the taser has some sort of inverter oscillator (like a 555 IC) that switches pulses into a step-up transformer, and then perhaps a stack of diodes to form a voltage quadrupler. ie. A bit like a line output stage in a television only miniturised.

This will current limit itself and not be able to provide much current due to the huge load that would be placed on the battery source, and the limitations of the switching device and transformer windings etc.

I'm guessing that perhaps its short circuit output capability is not more than 10mA or so???

[TheDaddy]

A very worthy volunteer methinks, it's a pity that I can't find the video on YouTube of the incident, apparently it was on there earlier

http://news.bbc.co.uk/1/hi/wales/north_east/6980867.stm

[Derek]

Originally Posted by TheDaddy

A very worthy volunteer methinks, it's a pity that I can't find the video on YouTube of the incident, apparently it was on there earlier

Another Chief Constable gets taser'd here:

http://www.manchestereveningnews.co....s_a_taser.html
http://www.youtube.com/watch?v=GIFl0q8dF1c

[TheDaddy]

Do you all get a turn at being tasered or is it strictly reserved for the bosses, could act as an incentive for them as well, don't give them Knighthoods for cutting crime, just don't taser them anymore