Change current of PSU

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

  1. nikos0608

    Thread Starter New Member

    Mar 3, 2013
    1
    0
    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.
    [​IMG]
    So...
    First i need to change the Transformer. I think this is ok, eh?
    http://www.hobbyking.com/hobbyking/store/__6256__12V_5A_110_240V_50_60Hz_Power_Supply.html

    The L200 IC can handle more current, as i can read in the datasheet (figure 21, 24)
    http://www.zen22142.zen.co.uk/Circuits/Power/l200.pdf

    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: http://www.zen22142.zen.co.uk/Circuits/Power/l200var.html

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

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    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......
     
Loading...