Help with power supply

Discussion in 'General Electronics Chat' started by javiramos, Jun 24, 2011.

  1. javiramos

    Thread Starter New Member

    Jun 24, 2011
    So I've got a circuit that runs an op amp at +15 and -15V relative to my power supply's ground. I want to use a small plug-in power supply instead of my bulky, lab one, but I can only find +15V or +30V power supplies relative to the power supply's ground. How can I get +/- 15V from a 30 V or 15V power supply? I really don't have much electronics experience so any help would be greatly appreciated! Thanks!
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    Just buy two 15 volt (isolated!) supplies and connect the -15 of one to the +15 of the other and call that connection point GROUND.
    KJ6EAD likes this.
  3. javiramos

    Thread Starter New Member

    Jun 24, 2011
    could I buy a +30V supply, divide voltage (with resistor) to +15V, call that ground, and then the -15V would be the negative terminal of the +30V supply?
  4. #12


    Nov 30, 2010
    yes, you can. As long as the current through the resistors is high enough that the "real" circuit you are building doesn't pull it too far off center.