why can you touch both sides of a 9V battery, you can even do it with a wet tongue and hardly get shocked, but a taser with that same battery can knock you out?
In: Chemistry
A little complicated and I’ll try to manage, but basically shocks are felt based on the amount of current that can run through you body. Think of it like a river, the faster that water can move down the river the bigger the chance of you being swept away with it if you stand in it.
Now think of your body as a dam, skin and even the tongue has thousands to millions of Ohms of resistance which restricts or resists that flow of water. So putting two and two together with a 9 V battery causes a very tiny amount of current to flow therefore no shock felt.
A taser is fairly different from just a battery since it’s able to create audible sparks of electricity. In order to make that spark it needs to literally break through air and make it to the other tip of metal. The resistance of air is crazy high and it’s the reason why the area where it sparks is very small. So in order to cross the gap that taser needs more voltage, something better than just a 9 V battery so it amplifies it (using complicated circuits and things that took me a year just to understand). This essentially changes a 9V battery into a car battery for just a small amount of time meaning that for maybe a couple tiny milliseconds if you taser someone they’re getting massive amount of current compared to just a 9 V battery.
Tl:dr things inside of a taser boosts a 9 V battery and gives you bigger shocks
The difference between a taser and a bare 9V is the voltage or potential being put across the contacts.
Broad electrical lesson:
Voltage (V) – potential or how much the electricity wants to move. Low voltage = lazy electricity, high voltage = Freight train coming from contact 1 to contact 2. Basically the higher the V number, the easier it is for electricity to move or “flow”.
Resistance (R or Omega) – The size of the pipe the electricity flows through. Copper wire = very low resistance or water main, Rubber glove = very high resistance aka brick wall. This resistance can be overcome by higher voltage.
Side note: resistance creates heat which is what causes electrical burns/how a toaster works.
There’s also Amperage (A) – ^broad ^strokes how much electricity is flowing. Not really relevant to tasers.
Tasers work by applying several thousand volts across the contacts where a 9V applies…well, 9 volts.
Tasers use circuits to
* increase the voltage (some models go to 50 000 volts)
* store the electricity from the battery in capacitors that can build up a charge over time and release it all very quickly
There are DIY taser type circuits on line if you want to see what the circuits can look like
Most batteries discharge their energy at a fairly slow rate. The battery might technically have the power to knock you out, but by itself it will only supply enough of that power to give you a little tickle.
A taser has capacitors in it, which are like short term batteries, they can store energy and release it a lot faster than a battery. So a taser basically takes all the power from the battery and puts it in a capacitor, and that capacitor releases all the energy at once, which is enough to hurt someone.
Edit: paper to power, lol.
Capacitors are basically tiny batteries. When you put two capacitors in series, you get the sum of their voltages. When you put them in parallel, you get the same voltage as any one of the capacitors. So, you can wire a pair of capacitors in parallel, charge them to 9 volts, then disconnect them. They continue to hold their charge while disconnected. You can then rewire them in series, and get 18 volts between them.
Imagine you have a circuit that simultaneously charges a whole bunch of capacitors with the 9v battery by wiring them in parallel. Once they are charged (milliseconds) the circuit quickly switches all of them out of a parallel configuration and into a series configuration.
If you do that with a 9v battery and 100 capacitors, you can output a 900v arc (more, if you use earlier stages to charge later stages)
Inductors can perform a similar function. The way an inductor works is by passing a current through a coil of wire. This creates and holds a magnetic field around the coil. When you disconnect power, the magnetic field suddenly collapses back into the coil. The collapsing magnetic field induces a huge voltage spike across the inductor. Depending on the input voltage, coil, and several other factors, the voltage spike can be several hundred volts.
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