Hello members of allaboutcircuit.com forum.i am in urgent requirement of design of 120 Volt D.C. and 5 or 10 Amp. Variable (0 to 120V) Power Supply. but i couldnt figure out which components i should use for this , i searched various websites but i could not get anyone fulfilling the criteria.may i use multiple circuits of lm 317(or any other power ics) in series to get this higher voltage. i already have a 0 to 64volt Variable 5 Amp dual power supply and i test it with load by connecting both the supplies in series just like a cell or transformer it works well, i communicated to the customer service of the supplier of the power supply in this regard but they told that it is harmful, and any damage will not be considered in warranty, hence i stop the practise.kindly suggest your opinionThanksanurag