I need a adjustable dual Power supply 0--->>+/-30v ckt as I am gonna build my bench supply. Please post a ckt if u have. But don't post ckt containing LM337 as I didn't find it here. Thanks in advance....
You can make that variable by putting a variable resister between the center pin (GND) and ground and put another resistor of 220 ohm between center and output pin. But remember the min voltage will be the regulator output voltage i.e if you use 7805, min voltage will be 5V.
Take note, the regulator ICs I mentioned above are +ve regulator type.
It,s best to use split 24V trafo (most Toroidal type hv) windings if you're not familiar with using single CT type. By using suitable pot in the Adj. pin you can vary the o/p voltage up to +/- 30V.