Power supply from 0V to 35V and current limiter up to 3A
Power supplies proposed by Elektor France, december 1982.
Photo from F4DCI Tony at http://f4dci.pagesperso-orange.fr/alim%20labo.htm
Note: without LM723 bin, I used a PIC with same number of PINs. So don't simulate it "as it".