high voltage low current

Discussion in 'General Electronics Chat' started by omar, May 12, 2009.

  1. omar

    Thread Starter Member

    Feb 19, 2008
    10
    0
    just wondering if you could help ...
    500 v dc with 0.5ma current , is it considered save?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    No, that is not a safe voltage.
     
  3. AlexR

    Well-Known Member

    Jan 16, 2008
    735
    54
    But it is a safe current and one would assume from those specs that if the current goes above 0.5mA the voltage will drop.

    Its current that does the damage not voltage but of course you need the voltage to drive the current.
     
  4. DonQ

    Active Member

    May 6, 2009
    320
    11
    Also, if it has a capacitor, even if the steady-state max current is limited, the impulse current (of discharging the capacitance) could spoil your whole day.

    This has to be considered an unsafe voltage, regardless of the steady-state current.
     
  5. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    I would never make such a dangerous assumption! How much will the voltage drop as the current rises? Is the system inherently current limited, or does it rely on some slow-blow fuse? Is it specifically designed for human contact? As little as 50V can push 600mA through a human chest cavity under the right (or wrong) conditions.

    Assume responsibility for your own actions, but never assume anything else!
     
  6. steinar96

    Active Member

    Apr 18, 2009
    239
    4
    The skin of the human body has a pretty high resistance until the voltage is high enough to break it. Since this voltage is 500V you can be pretty sure that your body won't be offering much resistance to current. Thus the current could easily be way higher then 0.5mA
     
    Last edited by a moderator: May 15, 2009
  7. THE_RB

    AAC Fanatic!

    Feb 11, 2008
    5,435
    1,305
    It's very unsafe even though the 0.5mA DC is unlikely to stop a HEALTHY human heart under controlled conditions the emotional "shock" of getting a big belt like that can cause big adrenaline release, massive involuntary muscle contraction when the person "jumps" etc etc.

    I almost tore a muscle once from the static discharge touching the car making me "jump". That same situation could have caused someone to have a heart attack.
     
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