well to give you a clearer pic of what i have and am trying to do,i have 10x 2n3773 pass transistors to use in place of the 3055's also a mc342p over voltage ic,the crowbar part etc is no probs,ive used the schematic i posted in the last thread before and had r8 switched between 120 ohm and 10k,that gave me 2 ranges going from about 3v low to about 28v high,in that one i used 6x pass transistors,the current foldback range didnt start untill about 5 amps,the 723 needs .6v to go into current foldback,the sg 80mv,im trying to build a psu that goes from about 3v to 30v say in 2 ranges and current limits from say 300ma to 30a,againe in say a high and low range,basicaly using the cct attached but with my own mods to it and using the sg ic,i see no reason why its not doable,my transfo is good for about 60a and my bridge rectifier is good for 180a,regards m3vuv.