pls help 0-30 Vdc and 5v Fixed power supply

Thread Starter


Joined Feb 19, 2007
good day! could anyone help me to construct a diagram/ circuit for a power supply with these specifications:
- output voltage 1: ---- 5 Vdc fixed
- output voltage 2: ---- 0-30 Vdc adjustable
- output current: 3A (minimum)
- full wave bridge rectifier
- input AC voltage is 220 Vac

please anyone... help me....
thnks a lot


Joined Apr 19, 2007
Hi.For the 5 volt fixed @ 3 amps, the LM323 will probably do the trick (with large heatsink).For the 0 to 30 volt supply, use an LM338 (with large heatsink), it is adjustable from 1.25 to 30 volts, or from zero using a 1.2 volt -ve ref.Spec sheets should be available on the web.If you need more help or schematics, let me know...Daniel.