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”

  • Dimitar February 2, 2011 at 12:40 am

    sylly question

  • admin February 2, 2011 at 1:00 am

    It's work because the current is sense on the NONE regulated side on the +32V, not at the output of 5 or less volt

  • gojo March 6, 2011 at 9:27 am

    can i get a proteus design of the circuit

  • reza April 9, 2011 at 7:14 am

    Dear Sylvain
    The Power supply project is so interesting. i have a problem. here in my location i could not find
    the ic LT1013, and there is no ZXCT1009 and D44VH10. can these elements be replaced by other popular elements?i.e to use 2n3055 instead D44….. and LM358 instead LT1013.
    about the ZXCT1009 is there a possibility of making a small circuit to do the same work az the Zx…?if the answer is yes please tell me where i can find it and what is the schmatic for it?
    Again Thanks for your project :D

  • admin April 9, 2011 at 4:31 pm


    For the LT1013 try to find any opamp that the supply is 40V. For the transistor you can a 2n3055, for the ZXCT I don’t know maybe you can do this with transistor, but I can’t help you for that


  • reza April 11, 2011 at 12:07 pm

    Thank you, about the GLCD can i use a KS0108 chip based Glcd instead of yours SED1330?

  • fejlong April 20, 2011 at 10:33 pm

    Excuse me,but how can a LM317 suply voltage be higher then its maximum alowed rating ,43V ? instead of 40V

  • admin April 20, 2011 at 11:18 pm

    That’s a mistake in the sch, Check for a higher voltage opamp like a lt1013

  • Matthew June 13, 2011 at 11:17 pm

    Could You please simplify you design so that I can implement your feedback loop and the AT mega 32 into a simple homemade benchtop from
    I am a student just starting EE work  and need power so this would be appreciated. Also you were featured on hack a day, Congratulations. 
    In the mean time I will get the transformers and the chip I already have some lcd screens. 

  • admin June 14, 2011 at 11:46 am

    Is it a joke? Modify my design for you, I don’t have time to make custom design for any boady, Only if you pay lots of $$$, and your idea will not work, the Mega will not be fast to detect a short circuit, your transistor will burn at first time…

  • storage shed delaware June 30, 2011 at 2:36 pm

    That is a great point to bring up. Thanks for the post.

  • Joe_ivp July 9, 2011 at 9:42 am

    Sylvain, are you sure about the 200 ohm resistor ? The version I made, a restored old PSU (preliminary page of photos, LCD not yet programmed etc)
    reaches only 21V @ 2.8A (using a 6R8 100W resistor as a load), because there is a ~11V drop across that resistor. There is 33V with plenty of current available but the 2N3055 base current is limited to 21V at a calculated base current of only ~45mA, meaning my 2N3055s have a gain of ~62, which would probably be similar to the D44VH10. In that case the resistor should be around 60 ohms, to allow at least 83mA base current and reach > 25V (allowing a few volts drop across the base resistor)
    Does that sound right to you ?

  • admin July 9, 2011 at 12:37 pm

    Hi Joe,

    Thanks for your email, 200ohms resistor is the value I use, it could be different, there is a lot of HFE that can change the calculation, but try like me to make test and find the good value for your transistor. a to low resistor will burn your output when you short circuit your PS

    I will no be able to answer you another time before 2 weeks I go in vacation

  • Joe_ivp July 9, 2011 at 11:27 pm

    Hi Sylvain, yes, I'll do some tests, and I realise the implications. Just thought I'd get your comment first. By the way, do you mention on the site here any particular procedure for calibrating V and I ? If not, what did you do ? Best regards

  • Sylvain Bissonnette July 17, 2011 at 12:59 pm

    adjustment is easy, set all your current & voltage pot to middle, power the board with no load, turn your outside voltage pot to the max (25V) and adjust the multiturn pot to reach the voltage,
    After ouput any voltage, short the supply output with a small load (ex 1A at 10V) and with your multimeter in serie of your load ajuste the current the same way as you did with the voltage 

  • jon.cher July 21, 2011 at 12:42 pm

    man you ROCK !! THanks for sharing your design … phew must be hardwork yeaa … i'll try it out >< hope i succeed … ^^

  • jon.cher July 21, 2011 at 12:47 pm

    btw … wat's de model of the lcd ? =3

  • Joe_ivp July 21, 2011 at 10:35 pm

    Thanks, sounds simple enough. I'm quite busy with other projects but when I have spare time I'm looking at various protection measures for the output, such as a crowbar or transistor/FET disconnect. And I'll be adding a switched relay to remove output power quickly from the load in an emergency. As with any PSU, the filter caps hold a lot of energy and would continue to supply current if you just turn the mains power off
    best regards

  • admin July 22, 2011 at 2:27 pm

    Take care, 90% of circuit need more than you can imagine of current to fast your “relay” will always open,

  • admin July 22, 2011 at 2:28 pm

    Thanks for your positive comments, yes you will succeed

  • admin July 22, 2011 at 2:28 pm

    SED1330 controler with 256×128 pixel

  • celica August 6, 2011 at 1:06 am

    i find your project  very interesting , very nice design , good job you have done !!!!

  • Giacomo Arru November 14, 2011 at 4:25 pm

    Thank you very much for sharing your projects with us, we'll try to reproduce your bench power supply with some little modifications.
    Here at our lab we all think you're a genius! You rock!

  • hywhook December 13, 2011 at 4:23 pm

    Hi, I congratulate you on the way you design and I ask a question, you could put complete materials list?     I would have to ask in another country because in Argentina do not sell and I would be missing something.
    from already thank you very much.
    Sebastian Cabrera

  • admin December 13, 2011 at 4:30 pm

    I don’t have time, already work 16h by day

  • Florin February 5, 2012 at 11:12 pm

    Hi, this is a very nice design, thanks for sharing it! There are some parts of it I don't completely understand though, I would be grateful for some further details.
    For example what is the purpose of the D3, R6  and Q3 around the current monitor? It is some kind of current amplifier? Isn't already the zxct 1009 acting as a current source?
    Also, the +5V input at the non-inverting input of the op-amps is playing the role of voltage reference, right? The what is the role of the +5V feed to the D7 and D8, and the R5 and R17 resistors?
    Hope I am not asking for too much!

  • admin February 6, 2012 at 5:16 pm

    D3, R6 and Q3 -> reduce the voltage for the ZXT that can’t support 45V
    zxt give a small current proportional at the voltage lost in R4
    Also, the +5V input at the non-inverting input of the op-amps is playing the role of voltage reference, right? yes
    R5 if to limit the current in the zener to protect your MCU of over voltage
    R17 with the cap c2 is to remove the noise from the potentiometer

  • Florin February 12, 2012 at 10:20 am

    Thanks, much appreciated! I plan to build two of them, isolated and without the MCU/display in the first phase. The only change I may try is to use another reference voltage (a lower noise one).
    However (and sorry if bugging) still not sure what the role of the 5V supply near the D6 and D8 is. Current shouldn't pass to the rest of the circuit and to the inverting inputs of the amps, because of those two diodes so what's the point of the 5V in that place? Thanks once more :)  

  • admin February 12, 2012 at 3:55 pm

    The 5V is the reference voltage you need to have a scall from 0 to 32v from 0 to 5v and the 2 diode is there to determin what the supply voltage must do, in overcurrent the opamp U1B win and in voltage control U1A win.


  • Asshole April 23, 2012 at 4:39 pm
    Check this transistor drinver
    you can make PSU with voltage and current you desire
    Also          !!!AWESOME DISPLAY!!!!
    can i use some of the 73-xxx-xxx and DMF-xxx displays shown here

  • Asshole April 23, 2012 at 4:42 pm

    Please dude tell me fast
    i will order my parts for my PSU and i need to know will these displays work
    please hurry up
    sorry for my english

  • Asshole April 23, 2012 at 4:56 pm

    this had to be first
    can i use your display?

  • Asshole April 23, 2012 at 4:56 pm

    you can mail me at

  • Sylvain Bissonnette April 23, 2012 at 5:05 pm

    You can use almost any single rail 40 opamp also 2n3055 will work but  200ohms resistor is the value I use, it could be different, there is a lot of HFE that can change the calculation, but try like me to make test and find the good value for your transistor. a to low resistor will burn your output when you short circuit your PS
    For the current sense, I don't have other idee, maybe you can try to find a circuit that will do the job. 
    I can help you more and I don't give the PCB files

  • Asshole April 25, 2012 at 3:39 pm

    dude do you saw my question
    please i'm in hurry
    answer me

  • admin April 25, 2012 at 3:52 pm

    You need a LCD with build-in SED1330 controller

  • Asshole April 26, 2012 at 6:00 pm

    ur gut dude
    thanks alot
    it would be good if you can tell me where to find these bitches
    if you can

  • Sylvain April 26, 2012 at 7:22 pm

    All at DigiKey, I can't help you more

  • Asshole April 27, 2012 at 1:02 pm

    you are awesome
    i suggest you look here
    this is the bes power supply (mc1466)
    it is a transistor controller
    line reg.0.02
    volt.reg 0.03
    voltage and current adjustable from 0 to X

  • admin April 27, 2012 at 1:10 pm

    Current from 0 to 5amp

    Voltage from 0 to 25V

  • Asshole April 27, 2012 at 2:10 pm

    the max. voltage and current depends on that
    how powerfull is the output trasnsitor
    if your transistor is 300v
    you can regulate it from 0-300v
    it controls the transistor
    current limiting included
    you can have power supply with unlimited power
    i think if you have around 1000000$
    you can make a PSU adj. from 0-1500v 0-1500a
    or more
    this is the block diagram of MC1466L

  • Asshole April 27, 2012 at 2:13 pm
  • Asshole April 27, 2012 at 2:17 pm

    also MC1466 is not produced anymore, so the block diagram is the only way

  • asshole April 29, 2012 at 1:10 pm

    hey dude
    about the diplay
    there is no such thing in digikey
    any ideas

  • asshole April 29, 2012 at 1:18 pm

    where did you get those displays
    please tell me!!!

  • asshole April 29, 2012 at 1:20 pm

    (reza)<-asked you:
    can i use a KS0108 chip based Glcd instead of yours SED1330?
    can i use KSO108 instead SED1330
    please tell me

  • asshole April 29, 2012 at 1:22 pm

    Sylvain please tell me

  • asshole April 29, 2012 at 1:23 pm

    you can mail me at

  • Jason May 31, 2012 at 3:24 am

    this is the most convoluted design there are much easier more stable and single source options available lt3080 for one which would also offer the ability to drive with a pic or avr like the other poster suggested

  • Slemi October 16, 2012 at 8:55 am

    Hi Sylvain!

    If you will ever make any changes, you can add a claculator in uC which calculates dissipated power on the transistors. If it's too high the backlight on display can blink so that you know it will overheat.


Post comment

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.



Electronic Links


AGC Anemometer AVR AVR Bootloader Bootloader Capacitence Capacitor Clock Color Control DCC Debugger Devices Digital driver Function Generator High Gain Microphone Humidity Inductance Inductor Laser LCD LED 3W Library Lightning Detector MegaLoad Meter Moodlight Mood Light MS5534 Nixie OscilloScope projector Rain Fall Sensor rgb RGB LED Scop Sensor SHT75 Temperature Terminal Tipping Bucket Train Modeling Vintage Water Detector