Get a positive and negative voltage output from power supply

Sometimes you may need both a positive and negative voltage output from a DC supply for applications or testing. To do this, you need to at least two DC power supplies or one with multiple outputs which has a floating output (not connected to ground).

When you have two single channel DC power supplies or a triple output power supply, here are some suggestions for you to get the positive and negative voltage outputs you need.

  1. Connect the two channels/supplies in a series configuration. This is done by connecting one of the power supplies’ (A) negative terminal to the positive terminal of the second power supply (B). This will be the reference and you may also connect this to ground or chassis ground.
  2. Now, power supply A will have an open port with the positive (+) terminal while power supply B will have negative (-).
  3. To get positive voltage with reference to ground, just connect between the connection of the series configuration of A and B and the positive (+) terminal on power supply A. Similarly, to obtain a negative voltage with reference to ground, connect between connection of the series configuration and the negative (-) terminal on power supply B.
  4. The settings should be as shown in the figure below. Now, you have both a positive voltage output and a negative voltage output.

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