Split rail power

Discussion in 'General Electronics Chat' started by vpoko, Apr 20, 2012.

  1. vpoko

    Thread Starter Member

    Jan 5, 2012
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    I did just recently post a power supply related question; I thought about adding this to that thread but I figure it's a different enough question to warrant its own thread.

    When using a DC bench power supply with multiple outputs that can be connected in series, I understand it's possible to have a split rail supply. The power supply I'm looking at (Mastech HY3005D-3) allows 0-30V on each output, but the specs don't mention being able to go to negative voltages. Does this mean if I use it as a split rail supply, I will have to choose a positive voltage as my reference ground? For example, if I need -15V, 0V, and 15V I'd have to choose 15V above earth ground as my reference ground? If I'm right, what are the implications for connecting an oscilloscope to such a circuit? Since the scope is connected to earth ground, wouldn't that create 15V of potential across its ground lead? Do I need a supply with a different feature set if I want to be able to get both positive and negative voltages out of it, with the ground being tied to earth ground? Thanks!
     
  2. t06afre

    AAC Fanatic!

    May 11, 2009
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    No it is quite simple. See the picture. Here I am using two 9 volt batteries. But the principal is the same for your two power supplies
    [​IMG]
     
    vpoko likes this.
  3. vpoko

    Thread Starter Member

    Jan 5, 2012
    258
    47
    Wow, it really is simple when you put it that way, thanks! Talk about a picture being worth a thousand words...
     
  4. Wendy

    Moderator

    Mar 24, 2008
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