4 ms·

Once you start getting into the thousands of volts, it becomes very dangerous. That stuff will arc through the air and kill you. There is a reason why we use

• userulluipeste 13y ago
  Not necessarily. If the connection would be unmanaged, as having the power available for drainage all the time, then you're right! ...but we have computers and all kind of complex systems now. The cable may be "empty" of that high voltage current until the cable is safely plugged in and ready. After plugging, before unleashing energy, the car's system and the power source's system may first communicate and verify their sensors if everything's ready to go, like isolation and other things. The high voltage risk and its management it's an engineering solvable problem.
  • cmccabe 13y ago
    You have the wrong idea of how voltage works. High voltage electricity can and will kill you before the ground fault interruptor (or whatever) can kick in. It takes time to break a high voltage circuit, (on the order of milliseconds), and during that time, you will die. If the current is across your heart it's especially lethal. If the voltage is high enough, there is no way to break the circuit anyway. The electricity will just arc across the (ionized) air, even if the computer physically disconnect it. Assuming the computer itself isn't killed by the spark, which is pretty likely. This is why linemen on high voltage lines don't even try to electrically insulate themselves when they're working with it live. Ask wikipedia: For high-voltage and extra-high-voltage transmission lines, specially trained personnel use "live line" techniques to allow hands-on contact with energized equipment. In this case the worker is electrically connected to the high-voltage line but thoroughly insulated from the earth so that he is at the same electrical potential as that of the line. Since training for such operations is lengthy, and still presents a danger to personnel, only very important transmission lines are subject to maintenance while live. Outside these properly engineered situations, insulation from earth does not guarantee that no current flows to earth—as grounding or arcing to ground can occur in unexpected ways, and high-frequency currents can burn even an ungrounded person. Touching a transmitting antenna is dangerous for this reason, and a high-frequency Tesla Coil can sustain a spark with only one endpoint).
    • userulluipeste 13y ago
      You understood wrong my statement. Assume that you have two independent connecting channels in the same connecting tube. One is a live low-voltage channel for communication protocol and the other one is high-power (but dead in idle) pumping channel. When you plug the tube you automatically connect both channels. After that, having the info-line established, having assured that the couple has been locked & safe (i.e. insulated), both systems might then agree on opening the second high-power channel. It won't matter if it will take more than a few milliseconds to open or cut the power with the tube being in a safe coupling state. By "safe coupling state" I mean that not even the contact with the possible ionized air is allowed, the line being covered/insulated all the way. You just design the systems to not allow power to drain from the source unless it's safe. I also think that it's already time to design all the systems like that, not only the high-power car-recharging ones. This would make a difference in lives saved.
      • cmccabe 13y ago
        Google "ground fault interruptor." What are you are talking about already exists. And it doesn't solve the problem.