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DC adapter supply question

Discussion in 'General Electronics Discussion' started by Sadlercomfort, Mar 11, 2013.

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  1. Sadlercomfort

    Sadlercomfort Ash

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    Feb 9, 2013
    Why can't I use a dc adapter to supply a variety of electronic circuits, instead of a battery? When using batteries my circuits will work fine, but using a dc supply from an ac - dc adapter gives me no power at all. The 12v adapter works fine and is tested. So there obviously something I'm not understanding?
     
  2. BobK

    BobK

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    Jan 5, 2010
    You got me. If the adapter is the correct voltage and can supply the needed current, the circuit should at least mostly work. There could be problems with noise in the supply, but to act like there is no power is puzzling. Did you try measuring the voltage witht the adapter hooked up to the circuit?

    Bob
     
  3. Sadlercomfort

    Sadlercomfort Ash

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    Feb 9, 2013
    Yeah It's really puzzling me too. I keep questioning whether im making a mistake because im still a beginner with electronics. I've also tried connecting a few different dc adapters into a voltage regulator module, which has a variety of input and output voltages. . but still getting nothing, as if its dead. But everything works with batteries. The voltage regulator module has a lcd display to indicate voltage, but doesn't even light up (unless using a battery).

    http://www.apogeekits.com/power_adapter_selection.htm - I've just found an interesting website which talks about how dc adapters only work properly at there designed voltage and current. Could this have anything to do with it?

    I'd really like to be able to use a dc adapter, because its more convenient for immobile circuits.
     
  4. BobK

    BobK

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    Jan 5, 2010
    Can you measure the voltage beteen the + and - (or ground) power leads from the powered device when using the adapater?

    Bob
     
  5. duke37

    duke37

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    Jan 9, 2011
    And, have you get it connected the right way round?
     
  6. Sadlercomfort

    Sadlercomfort Ash

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    Feb 9, 2013
    Turns out it was a beginners mistake =] I tested my positive/negative pins directly from my adapter and got around 13v. Then I plugged my adapter into my dc jack plug, which is connected to my voltage regulator and test between +/- at the input from voltage regular and got 0V?

    So I tested my dc plug to see where the open circuit was, and found that my dc plug had 3 pins? And my negative wire was connected to a dud pin (not connected to anything) So re-soldered it to the other pin, and it works great :D
     
  7. davenn

    davenn Moderator

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    Sep 5, 2009
    Great to hear

    always a satisfaction gained in finding a fault no matter how simple of complex :)

    Dave
     
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