PSU noise

Discussion in 'Electronics & Electrics' started by warrenr, Jul 4, 2018.

  1. warrenr

    warrenr Member

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  2. kjparker

    kjparker Member

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    Stupid question... Have you tried a different PSU? 3a is not outside of the realms of a plugpack, or even an ATX power supply?
     
  3. aXis

    aXis Member

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    On those open frame supplies, I like to link the DC negative terminal to the earth terminal.

    Not only does it help suppress some of the noise but it will give some protection (by tripping your RCD) if the PSU isolation fails and puts mains voltage on the DC outlets.
     
  4. OP
    OP
    warrenr

    warrenr Member

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    I went with the smaller PSU (this thing is literally the size of a pack of cigs) as I wanted to keep it neat on the machine. you're right though - I could use another supply, but havent tried.....

    interesting! Will give it a go - any reason why they dont wire it like out of the box though? :Paranoid::Paranoid::Paranoid::Paranoid:
     
  5. aXis

    aXis Member

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    They way they supply it, the DC is isolated and floating which can be handy in some scenarios. Technically it's safe and valid to do this.

    Personally I dont like it though. Cheap / Low quality PSU's have been known to fail isolation and superimpose mains voltages onto the DC lines, which has then killed people. Linking the DC negative to the earth provides a good safeguard.
     
    Last edited: Jul 5, 2018
  6. kjparker

    kjparker Member

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    I get where you are coming from, however my point was more around for the testing side of things. Try another supply, even an old PC PSU, and if the problem goes away, you know that the small supply is the fault...
     

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