Many times we needed a stabilized, together regulated power supply and high relatively output voltage. These specifications him it cover our circuit. It 's a circuit that can give in his exit + 40V until + 60V 3A, with simultaneous stabilization. The materials that use is very simple and will not exist difficulties in the manufacture, is enough you are careful certain points. 1 ] For output voltages smaller of + 50V until + 40V, the Q1 is hot enough, so that it needs one big heatsink. 2]For output voltages bigger of + 50V up to + 70V, the stabilization is not satisfactory. Conclusion: ideal output voltage is + 45V until + 60V. In the circuit pontesometer RV1, is used in order to we change the output voltage between + 40V until + 70V, we can however and perhaps it should, him we replace with two constant resistors, when finishe the regulation, in the desirable price. The reason is, that with time is presented change of output voltage, up to 3V, with connected pontesometer. ATTENTION!!! The positive exit correspond in point [ A ] and the exit of 0V in point [ B ], which should not be connected in the ground.