Bench Power Supply 0-25v @ 0-5amp
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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.
Features
- 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
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74 Comments to “Bench Power Supply 0-25v @ 0-5amp”
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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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Sorry,
sylly question
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
can i get a proteus design of the circuit
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
Hi,
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
Sylvain
Thank you, about the GLCD can i use a KS0108 chip based Glcd instead of yours SED1330?
Excuse me,but how can a LM317 suply voltage be higher then its maximum alowed rating ,43V ? instead of 40V
That’s a mistake in the sch, Check for a higher voltage opamp like a lt1013
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 http://www.wikihow.com/Convert-a-Computer-ATX-Power-Supply-to-a-Lab-Power-Supply
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.
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…
That is a great point to bring up. Thanks for the post.
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)
http://home.clear.net.nz/pages/joecolquitt/sylvain_psu.html
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 ?
Joe
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
Sylvain
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
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
man you ROCK !! THanks for sharing your design … phew must be hardwork yeaa … i'll try it out >< hope i succeed … ^^
btw … wat's de model of the lcd ? =3
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
Take care, 90% of circuit need more than you can imagine of current to fast your “relay” will always open,
Thanks for your positive comments, yes you will succeed
SED1330 controler with 256×128 pixel
hello
i find your project very interesting , very nice design , good job you have done !!!!
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
I don’t have time, already work 16h by day