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Discussion in 'General Electronics Chat' started by Cburg, Jul 12, 2012.

  1. Cburg

    Thread Starter New Member

    May 16, 2012
    Dear Moderators,

    Please excuse my ignorance. I did not realize that this was dangerous. I am using a kit that is publicly marketed; a strobe light kit. I wondered about this, but thought it must be OK if it is sold to the public.

    Thank you for your guidance. I will incorporate a transformer, and will use a different schematic program.

    Again, thank you for your help, and my sincere appologies!

    Best regards,
  2. Cburg

    Thread Starter New Member

    May 16, 2012
    PS: Could someone explain why non-isolated power supplies are dangerous? I have never understood this.
    Thank you!
  3. strantor

    AAC Fanatic!

    Oct 3, 2010
    with an isolated supply, you have to touch both sides to get a shock. With a nonisolated one, you only have to touch one. That, and the isolated supply is less likely to be able to deliver enough current to kill you, whereas mains is very good at doing just that.
  4. justtrying

    Active Member

    Mar 9, 2011
    to expand, the problem is that in non-isolated supply, PCB shares its ground with main and in an event of a single fault, the user is shocked just by touching single side of the device. With isolated supply, the user is protected from a single fault condition (such as broken ground wire) and another fault would have to occur to result in shock. Non-isolated supplies have to be double insulated to minimize danger.

    There are more reasons for isolation "Grounds for Grounding:A Circuit to System Handbook"
    Last edited: Jul 13, 2012
  5. PaulEE


    Dec 23, 2011
    Plastic. Box. :)
  6. Cburg

    Thread Starter New Member

    May 16, 2012
    That's what I had planned; with no exposed screws. The mods, however, don't seem to think this is adequate.
  7. Wendy


    Mar 24, 2008
    It isn't. Somewhere there will be a electrical connection or wire on the outside, and it will be dangerous. Anything powered by such a setup is also dangerous. It is not just the mods, anyone with real experience understands the problems.

    Given that we have many beginners here, you aren't just talking to a small circle, but the world of people who have come to visit and learn.
  8. Cburg

    Thread Starter New Member

    May 16, 2012
    I respect that.

  9. jwilk13


    Jun 15, 2011
    I've been on the receiving end of a shock from one of those strobe light kits...and I thank the moderators for trying to keep it from happening to others :)
  10. GetDeviceInfo

    AAC Fanatic!

    Jun 7, 2009
    I've worked many years with high voltage mains capable of delivering thousands of amps. I employ a system of checks before going anywhere near such power, and treat it with the greatest of respect.

    The problem with the lowly 115vac 15amp branch circuit, is that it's taken for granted. In hobby project work, it is all too often that mains power is not properly terminated, mechanically/electrically isolated or strained.

    In forums such as this, advice is often given with certain assumptions, primarily that good practices are employed. Recognizing the inherent danger, the forum abstains from discussing projects that could expose one to these dangers.

    It's a good position and one that should be respected.