Unipolar to Bipolar converter help

Discussion in 'General Electronics Chat' started by ankyk91, Mar 20, 2013.

  1. ankyk91

    Thread Starter New Member

    Mar 19, 2013
    Hey there,

    I am just starting to learn about PLC at my new job.

    The supervisor has given me a task to design and build a circuit that would be able to produce the following voltages for a AI PLC.

    0V to +10V
    -10V to +10V
    -5V to +5V
    0V to +5V
    +1V to +5V

    I was only given a 24VDC power supply, a voltage regulator (24V to 10V) and a variable resistor.

    The first task was to be able to make the unipolar supply 10V into a bipolar using op-amps.

    I did my research and found out that a differential amplifier circuit using op-amps would be the prefect unipolar to bipolar converter.

    However, I am confused regarding which op-amp would be the best of this kind of circuit esp since I only have a single supply but still need a rail to rail voltage.

    Thank you....
  2. crutschow


    Mar 14, 2008
    A differential amp can't convert voltage to a polarity that is different from the supply voltage(s). It can't convert a unipoplar supply to a bipolar supply. For that you need a switching power supply. For low currents you may be able to use a switched-capacitor design. For more than a 100mA or so you will need a switching supply using magnetics.