Is this shocking?

V

vic777

Well-known member
I think I know the answer but ....
If you are in the bathtub ... and you drop your laptop in the water ... it is on but operating on the battery, not plugged into outlet ... battery power only ... will you get an electrical shock.? If the electrical cord is attached, for dramatic effect, but not plugged in, however the laptop is on, running on batteries ... for dramatic effect .... will anyone get a shock?
 
Normally, no. The reason for this is in a DC circuit, to get a shock, you have to put your self between the negative and the positive, which is self-contained in the battery/laptop. Electricity takes the path of least resistance. With AC, the neutral eventually goes to ground; and water, via the piping, etc., provides that shorter path. But the human body is more conductive, due to more electrolytes than just water. Hence if you are in the water and you are in the path to ground, you are a lower resistance than just the water.

But there is the slightest chance if the actor is holding the laptop just right, when the battery shorts, they could still be injured if the battery overloads and explodes. If you are going to do this, pull out the battery as well for safety.

EDIT: AC from a wall outlet (120VAC) aka: house power
 
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The laptop may convert DC to AC for various reasons, and so a slight shock could occur.

See:
http://en.wikipedia.org/wiki/Switched-mode_power_supply

"Most laptop computers also have a DC–AC converter to step up the voltage from the battery to drive the backlight in the flat-screen monitor, which typically requires around 1000 VRMS.[14]"

also

"If a diode-and-capacitor combination are placed in parallel to the switch, the peak voltage can be stored in the capacitor, and the capacitor can be used as a DC source with voltage higher than the DC voltage driving the circuit. This so-called boost converter acts like a step-up transformer for DC signals."
 
polfilmblog said:
The laptop may convert DC to AC for various reasons, and so a slight shock could occur.

See:
http://en.wikipedia.org/wiki/Switched-mode_power_supply

"Most laptop computers also have a DC–AC converter to step up the voltage from the battery to drive the backlight in the flat-screen monitor, which typically requires around 1000 VRMS.[14]"

also

"If a diode-and-capacitor combination are placed in parallel to the switch, the peak voltage can be stored in the capacitor, and the capacitor can be used as a DC source with voltage higher than the DC voltage driving the circuit. This so-called boost converter acts like a step-up transformer for DC signals."
Click to expand...


But keep in mind, the AC you are discussing is not the same as AC from an outlet. The AC from an internally generated source is a closed loop. The voltage source is the battery (which is ultimately DC), since it is not connected to a wall outlet where the earth itself is a source of voltage return. I could take a single lead (positive or negative, not both) directly from the battery of a laptop and connect it directly to a ground rod and as long as there is no other path (having the AC or other cable connected and plugged in, cable shorted to another area of the laptop), nothing would happen. It is a closed circuit.

Also, even if the voltage if extremely high, you also have to think of amperage in conjunction with the voltage. My body has been a conducter of 1.5 Megavolts (1.5 million volts) AC @ less than .1 microamps, and got nothing but a tingle. But hospitalized with 48 V at 20 A.

Either way, not a good idea, but needed to clear this mis-conception up. Vic, if you are going to dunk this laptop, have the scene where it is actually going under shot with no battery installed and not actually showing the front screen but from the back of it. Go and buy one of those 2-3 AA battery powered florescent lights (about 6 inches long) or a couple of the hockey puck push-on LED lights, tape it to the front of the screen. This way you are showing the "light" from the screen on your actors face, but not depending on the screen power itself. It actually works good.

LOL, wikipedia. Always just enough info to convince people they are right, or in some case, be dangerous.
 
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Also, for safety, cut the plug end of the power cable off. This will ensure that it is not accidently plugged into the wall outlet by a well-meaning but misguided PA. Most laptop power supplies use an IEC power cable that can be replaced for a buck or two, so the power supply will still be good.
 
If you're going to do the scene make it a shocker. Charge the battery fully, then cut or break the metal off the plug. Glue or double stick tape the plug to wall. Put double sided tape between the socket and plug head. Take the battery out before shooting the scene where the laptop falls in. I hope this is a cheap laptop you got from a pawnshop. This will give the appearance of a full functioning laptop that's plugged up. Most people power their laptops via battery if they're using it in the bathroom because they don't want to get shocked, but no one expects the computer to fall in the tub either. (I'm assuming someone is going to throw it into the tub so maybe you could cut to someone plugging the computer up then bring in the dummy plug and "stunt" computer, LOL).

-Nate
 
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