Change current of PSU

Discussion in 'General Electronics Chat' started by nikos0608, Mar 3, 2013.

  1. nikos0608

    Thread Starter New Member

    Mar 3, 2013
    Hi, i am studying electronics and i got a project from my teacher...
    He gave me the following circuit and he asked me to make it output 5A instead of 2A. The voltage and current outputs must be regulated.
    First i need to change the Transformer. I think this is ok, eh?

    The L200 IC can handle more current, as i can read in the datasheet (figure 21, 24)

    so, my questions now...
    first, in the schematic isnt there a mistake? At the IC, i think pin-2 should be pin-5 and reverse?

    2nd: if i add the BWD52 with an R=2.5Ohm to pin 1 and collector of transistor to pin 5 (with the 47 Ohm potentiometer) i will get up to 5A output?

    3rd: If i get the 5A output, do i have to change the electrolytic capacitors to bigger?

    Link of the project:

    Thanks in advance!
    If someone could design the circuit for me, it would be great :)
  2. bountyhunter

    Well-Known Member

    Sep 7, 2009
    A transformer with a 2A RMS (AC) current rating on it's secondary winding can NOT deliver 2A of DC load current using a FWB with cap filter as shown in the schematic. It would actually take a transformer with a secondary of about 3.2A RMS.

    If you have an instructor who believes it can, this may be a case of blind leading the blind......