power supply for op amp experiments

Discussion in 'The Projects Forum' started by Neil Groves, May 26, 2015.

  1. crutschow


    Mar 14, 2008
    That circuit only works if the positive current equals the negative current. For example if you try to draw slightly more positive current than negative current, there's no place for the excess current to flow from the ground to the 15V supply.

    Here's a circuit that will properly work with unbalanced loads.
  2. ScottWang


    Aug 23, 2012
    Thanks, I will try what you mentioned.
  3. atferrari

    AAC Fanatic!

    Jan 6, 2004
    When I started, after many PSUs built in rush one day I decide to build a dual +- 5 9 12 15 18 plus a small dual variable +- 1,25 to 22V. Please do not confine your decision based on you needs today.
  4. hp1729

    Well-Known Member

    Nov 23, 2015
    LM317 and LM337 won't over-current until 1 amp or more. Lots of smoke can be released before that time. For op amps these devices also come in TO-92 versions limited at 100 mA. Making your own power supplies is the way to go in my opinion. Battery power is okay.
    Other nice things to have is variable voltage sources. An op amp in a buffer configuration with a pot on the input.
    Some examples of support circuits I have built over the years. I suspect others have their favorites also.