Hello guys

It is another instructable and it is about making Bench power supply

I made it long time ago and I still use it on my bench so I decided to share this project with you my friends.

I'm not recommend it to you and I think the best thing to do is, to buy a standard bench power supply and use it on your bench but for someone like me who do not have too much money to pay for high quality bench power supply this power supply work fine.

It deliver enough power and could cover a big range of voltage and current. This power supply has too much power ,so if you decide to make it do it on your own responsibility and be careful to do not damage your circuit.

Step 1: What Is It

The base of this project is computer power supply and couple of dc-dc converters that could convert the pc power supply from 1v up to 86v and 100mA up to 10A, so as you see its cover a big range of power.

I used two dc-dc converter. One of this converter could converter 12 V up to 86 V up to 10 Amp and another one could provide 1-30 v up to 5 Amp so you could cover a big range of power.

My Pc power supply output:

12v, 15A ,

5v, 25A,

3.3v,17A

-12v, 900mA.

I upload the original photo off the modules I used in this project.

Step 2: Material and Tools

List of Material:

-Pc power supply(I had one from an old pc)

- DC-DC 600W 10-60V to 12-80V Boost Converter Step-up Module

-6-35V to 1-35V DC/DC Buck/Boost Charger Power Converter Module

-Small 3.3-26v boost conveter(I used it to convert 3.3v of my pc power supply to 12v to run the fans)

-Dual LED Digital Voltmeter Ammeter Amp Volt Meter + Current Shunt DC 100V 50A

-Two enclosure (or one big enclosure to fit all the electronic part in it easy)

-Two 100k potentiometer

-Two fan

-Banana plug

-Banana socket

-Two switch

-Aligator clip

-5r 10w resistor

-0.51r 5w resistor

Tools:

-Soldering iron

-Hot glue gun

-etc

Step 3: Wiring and Setting Up

In my case I used 12v, 5v and -12v and GND line of course.

My pc power supply has about eight 12v output wire so I have enough access to 12v output to feed the both dc-dc converter. I feed the big module with five wire and the small wire with three wire, so they could provide enough power. The big module convert 12v up to 86v and could provide about 600w maximum and, the both voltage and current are variable in this module. The second module is boost-buck converter, so I feed it with 12v and it provide output voltage of 1-30v and provide up to 200w. this module only have variable voltage and unfortunately have not variable current. You could use current limiting for your circuit. I upload the original photo off the modules I used in this project.

Step 4: Adding Resistors and Dual Led Ammeter

in this step I put a 5r 10w resistor between 5v and GND of my pc power supply to make it more stable.

Now I start to assemble the led Ammeter. This Ammeter has dual led( the blue one is current and the red one is voltage) I uploaded the wiring diagram of Ammeter and how to set the current shunt.

The shunt help the Ammeter to show the current correctly. Then I replace the dc-dc converter potentiometers with 1/2w linear rotary pot because it's easier to place the linear pot into the box

I put a led with 1k resistor for on-off switch and cut top of the box to set the fan and few holes in other side of the box so air fellow is easier.

To turn on the fan I used one of 5v wire of the pc power supply and add a small boost converter and fixed the voltage on 12v, so the fan will work properly.

Step 5: Final Assembly

Finally I made hole for potentiometers and secured them in place and five more hole for banana plugs. One for -12 one for +5, one for GND and two for adjustable power output. and then I fit all the component and wires inside the box and now it's ready to use.