Bench Power Supply 0-25v @ 0-5amp

Author admin    Category Work Bench Tools     Tags , , ,


This project is like the one that all of you must have done in electronics.  I took the idea from Circuit Cellar. The original power supply provides an output of 2.5-15V at 500mA. This circuit will provide 0-25V at 0 to 5A. You will see there is a lot of modification to achieve this.

This is my second version of this power supply, the first one was made with mosfet who need a higher voltage on the gate I had to use a higher input voltage and because of this there was a lot of heat generated for nothing.  This version work with transistor and it's much more better. 

    I will explain you some part of this power supply.  First you must find a transformer which can handle 24VAC at 5A and one with 6.3VAC at 100ma.  I use 2 transformator to have 2 DC level 30V and 40V. The 30V Power the high current for the output and the 40V power all the rest of the circuit.  The LT7013 opamp is split in 2 function, the part A is the voltage control and the part B is the current control both opamp output is connected together via diode so the one who output a lower voltage win on the second, so if you set your voltage to 10V and your current to 1A and you short your ouput the current part will pull down his output and the voltage will drop.  The current part use a very nice component the ZXCT1009 that work like a current mirror.  it will generate a current proportionally the the one who pass in the sense resistor, this current is pass in the pot R8 who convert it in voltage.  The output have many transistor because the opamp can't give a lot of current, and note that the resistor R23 is very important, this one will protect your output transistor from a output short circuit "transistor explosion is faster than the current sense".  If you build this supply you will be impress how fine it's work.

    I also connect to this power supply a LCD to inform you of the set point for voltage and current, plus the current voltage and current.  It's done with a small ATMega32 with 4 A/D input to received the value from the power supply and with some simple calculation it display those value.




  • Output Voltage adjustable from 0 to 25v
  • Output Current adjustable from 0 to 5amp
  • Digital reading of set points for current & voltage and output current & voltage.
  • No need of multi tap transformer or center tap transformer
  • Short circuit protected
  • Very low cost



PowerSupply Schematic

Graph LCD Schematic

Graph LCD Source Code

123 Comments to “Bench Power Supply 0-25v @ 0-5amp”

  • sey cat's boy October 28, 2012 at 3:30 am

    Thank you, Sylvain!
    This is really necessary for me.
    But I have a few questions for you.
    First, Did you use any compiler?
    Second, Y1 (in your Graphic LCD circiut) <=What's it? crystal devices?
    Third, R3 (in your Graphic LCD circiut) and  R11 and R12, R19 in your PowerSupply Schematic What roles?
    Thx Sylvain! and Sorry, I some rude.
    please forgive me.

  • admin October 28, 2012 at 4:01 pm

    r11 and r12 is the voltage & current ouput value
    r19 set the 32v voltage regulator
    I use ICCAVR
    Y1 is a piezo buzzer

  • martin October 29, 2012 at 2:58 am

    you can substitute the ZXCT1009  by an acs712 (5amps)  and recalculate the resistors for the voltage output … in the circuit   since it will need 0 to 5 volts for the current limitter circuit

  • ginpb December 2, 2012 at 11:09 pm

    Hi nice project any info about the ripple?.

  • admin December 3, 2012 at 2:06 am

    Thanks, the ripple is less than 0.01volt

  • MIkle December 4, 2012 at 5:03 am

    Hi! Very nice project !
    what is model lcd you're device? WG12864K-YYH-VN will be work? 

  • admin December 4, 2012 at 12:52 pm

    I don’t know, you need a lcd with a sed1330 controler or compatible one

  • kepler December 4, 2012 at 12:54 pm

    Hi, could you tell me the reference or part number for the LCD screen you are using? Is there a datacheet availaible for it?  I would like to build somethng similar, thank you.

  • admin December 4, 2012 at 12:55 pm

    It’s no longer exist, I had try to buy other one last year and nothing is available

  • MIkle December 5, 2012 at 4:47 am

    I think analog SED1330 this KS0107/KS0108. I'm buy WG12864K-YYH-VN and check.  Thank  you!!

  • hobbyist January 31, 2013 at 7:28 pm

    has somebody found a working display for this project?

  • Nic Ma April 25, 2013 at 2:34 am

    What would it cost to make this? What modification would be needed if used with european 230V?

  • admin April 25, 2013 at 2:36 am

    Lost of $$$, change the transfo

  • hosein April 29, 2013 at 10:57 am

    hi  thanks for project
    i want make this project but  i cant open source cod with code vision !!!
    and i dont see this header files    #include <iom32v.h>  and   #include <eeprom.h>

  • admin April 29, 2013 at 2:06 pm

    All my projects are written with ICCAVR and the code can’t not be compile directrly and I can’t help you with that,


  • hosein April 30, 2013 at 8:00 pm

    i cant found  this lcd !!  i have graphic lcd model :  ts12864a-2/b   the pins not match   please help me

  • Sylvain May 2, 2013 at 12:47 pm

    I can't help you I don't know this LCD with is controller

  • Nicolas December 9, 2013 at 9:57 am


    Nice power supply you have built there. Thanks for sharing it.
    I happen to have some tip33c transitiors lying there, may I switch the D44VH10 with these?
    Also, I have a 230V to 2×40V transformer (5A). Can I use it instead of a 30V and a 40V transformer? Or will 40V be too much for the high current side?
    Last question, what is the power rating for R20, R21 and R22?

  • admin December 14, 2013 at 2:16 pm


    Yes it should work with oter transistor, but you must change the value of R23, Yes you can change the XFO but P=IE… if you need
    to output 1V at 5A you will loste 39V at 5A lots of power very huge heatsink

  • carlos December 24, 2013 at 9:47 pm

    Good project!
    I just wanna know if is possible not use the devide "header 5X2'. 
    Is it really necessary? What does it do?
    By the way is an RS-232 output connection?
    Thanks a lot.

  • admin December 24, 2013 at 10:10 pm

    if the header is connected to the mcu that’s the programation port
    no rs232

  • Tom May 30, 2014 at 10:29 am

    Might increase the out voltage 30V?
    Thanks Tom

  • admin May 30, 2014 at 1:45 pm

    not with this design, then max could not be over 26v

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Please note

All my source codes were taken from my personal projects.

Everything is for your information only. The C/C++ codes have been written
with ICCAVR. You can find the header and source CRT files by downloading their compiler.

All is for your information and everything is AS IS without any warranty of any kind. No other files are available and I don't make any modification for any body.



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