and they put out a lot more energy (few hundred J) than two PSU caps.
I call bullshit. Sorry but a typical switched mode PSU primary cap contains enough voltage and current in it to stop your heart. It only takes a couple of milliamps to cause fibrillation.
http://www.physics.ohio-state.edu/~p616/safety/fatal_current.htmlhttp://van.physics.illinois.edu/qa/listing.php?id=6793http://van.physics.uiuc.edu/qa/listing.php?id=1339It takes about 100 mA of current to kill you. Even currents under 75mA your breathing can stop completely, which can kill you.
Provided certain conditions are met, an input cap on a PSU has more than enough current to kill you.
A basic US household switching power supply has over 350VDC in it's primary. 350VDC WILL go through your skin which (when dry) has a resistance of 1,000 to 100,000 ohms depending on thickness and if it's burned or open. Burnt skin allows for an open wound which will readily conduct more current. Granted that the internal resistance of the human body varies depending on muscle content and other factors... Considering this was a kid I'm willing to think:
A. He has no calluses on his hands and the skin on his hand is fairly thin.
B. I'm not assuming he has much muscle as most teenagers aren't very musclebound... most certainly those inclined to work on their family computer.
So assuming those factors we'll take his total resistance:
Rtotal = Rskin(in) + Rinternal + Rskin(out)
Perfect condition:
Rskin(in)= 1000ohm (This is the "Input" resistance)
Rinternal= 100ohm (being generous here as more muscle = more resistance)
Rskin(out)= 1000ohm (This is the "output" resistance)
I=V/R so I=350VDC/2300ohm
350VDC/500ohm=.15A
Best case Scenario (Older gentleman with lots of muscle mass and calluses):
Rskin(in)=100,000ohm
Rinternal=1000ohm
Rskin(out)=100,000ohm
340VDC/201,000ohm= 0.001A
Plausible scenario:
Rskin(in)=1,500ohm
Rinternal=400ohm
Rskin(out)=1,500ohm
340VDC/3,400ohm=.1A
Likely scenario:
Rskin(in)=2,000ohm
Rinternal=500ohm
Rskin(out)=2,000ohm
340VDC/4500ohm= .0755 repeating
Enough to stop breathing.
Depending on the person, it's
more than enough to kill you.
Regardless we don't have his skin resistance measurements, we don't know if he had any open wounds which would have readily conducted the current, and we don't know anything other than what they released in the news. Saying a cap CAN'T kill you is negligent and voiding respect for electricity.
ANYTHING. ANY CURRENT can kill you. Period. It just depends on all the factors and if the moon is lined up.
People survive lightning strikes... but capacitors can kill you. Just depends if it's your day or not.