HI everyone, this is my first post so i am expecting a lot from this forum (basically also my first time asking for help on a forum).

I am given a project to design a dc power supply with
1. centre-tape transformer (220-V AC to 24*2 V AC).
2. LM-317 ic.

I can't use any transistors or any other ic's, so can anyone give me some ideas on how to do it?

my design works from 1.25-30 volts DC. But i couldn't understand how to drop those 1.25 to 0. since Vout=1.25*(1+R2/R1).

 

You'll not get much help cross posting.

 

You'll not get much help cross posting.

sorry, i wrote it in wrong place, but didn't knew how to delete it...
sorry again... :-(

 

Hello,

The other thread is here:
0-30 Volts variable DC supply without using any transistors

Bertus