bench PSU 0-->15V 0-->3A

[Ahmed_MK]

I watched a couple of videos on lab power supplies by Dave and I tried to attempt to make my own.
*check attached image

I am a beginner and It is my first electronics project.
I have not finalized it.
However, I have a couple of questions on OP-AMPS and On the way I attempted to get negative voltage.
    1. In the data sheet for the op-amps it says  "All voltage values, except differential voltages, are with respect to the midpoint between VCC + and VCC −"
        and it says Vcc =( + or - ) 18V.
        does that mean I could put +28.6V volts and -1.4V such that the range is less than 36V?
        *I would do that since the opamps used are not rail to rail
    2. Also, Proteus fails to simulate this circuit, it says too many iterations.
Furthermore, I would appreciate any advice you can give me?
Appreciated

[mikerj]

does that mean I could put +28.6V volts and -1.4V such that the range is less than 36V?

Yes, the supply rails do not have to be balanced.  Having a small negative voltage rail is reasonably common to allow the output of the op-amp to swing down to a true 0v.

I have no idea about Proteus though I've never used it, sorry.

[Benta]

Why not just use a TI LM350K?
You'll need a negative bias voltage to get it down to 0 V output, but that's a nice little exercise.

To generate a negative supply voltage, this little circuit is great. You just need to make sure that the main (positive) supply line pulls more current than the negative.