Power Supply




Introduction: Power Supply

About: I am a student of BSCS but I'm interested in electronics that's why I would like to think about innovative ideas and try to build my ideas into reality and i also interested in making a robots. email id: deg...

Hello! friends

Welcome to my another DIY "Power Supply" project. In this project i'm gonna show you how to make your own power supply with old computer. I have my old pc so, i decided to change it into something new like power supply + 5 volt charger for my workbench. So, let's get started.

Step 1: Circuit Diagram

Here it is the circuit diagram and some information about power supply wires with the help of this we will be able to make our project.

Step 2: Components and Parts

You'll need

Switches: spst x 2

Resistors: (5 watt 12 ohms x 2) and (1/2 watt 2.2 k x 2)

Led: Red and Green

Female usb port x 2


Drill and Drill bits according to the size

Terminals x 6 (one black for ground and 5 other any color)

5 volt 2amp charger kit

Hot glue


Step 3: Removing All Parts From Old Pc

Remove the all parts from your old computer you don't need anything except power supply and 12 volt fan. Make sure don't waste your removing parts we will use later for another project.

Step 4: Casing and Strips

Now you have computer casing and two strips of floppy drive and CD-ROM drive. Take your floppy drive and CD-ROM drive strips.

Step 5: Measuring and Holes

Take your floppy drive strip and marking on it according to terminal size. I marked for 6 terminals and than hole on it.

Now take your cd-rom strip mark on it according to the voltmeter cut it down into the box shape.

Step 6: Fixing

Fix your all 6 terminals into your floppy drive strip and put a voltmeter into the cd-rom strip. Than its look like this.

Step 7: Disassembling the Front Side of Pc Casing

Take your pc casing and remove the front pannel from it than its look like this.

Step 8: Removing Circuit

Remove the power and reset circuit + usb port from it and than placing it onto the vero board and cut it down according to the same size and build a circuit on it.

Step 9: Making Circuit

Now build your own circuit of on/off for your power supply according to your circuit diagram (1) and make usb port connection according to circuit diagram (2) placing the all components on a both strips and then soldering it.

Step 10: Power Supply Wires

Take a bigger clip of wires and cut the clip you don't need this you need wires only.

Step 11: Installing Parts

Put the all parts back "usb port, floppy drive strip and cd-rom strip" into the casing and make some connection according to circuit diagram (2) with soldering.

Step 12: Connections

Take a small piece of veroboard and soldering two 5 watt 12 ohms resistor into paraller and connect one end with +5 volt and other one is from ground. Joining the wires with voltmeter also connect your 5 volt 2 amp charger with it according to the diagram and soldering it with female usb port.

Make sure you'll soldering the all components accoding to the diagram very carefully.

Step 13: Fan Plugging

Remove the cover from 12 volt fan which one we take it while disassembling the casing parts. Now you'll need to fix it back with computer casing and connection it.

Your power supply is almost ready to use.

Step 14: Voltage Checking

Check the output connections with your meter for your confirmation its working fine. Fix the all components with hot glue very carefully.

Step 15: Finish

Now my DIY power supply is ready to use for my workbench here above on and off conditions of my power supply you also check the voltage reading on voltmeter.

I hope you guys like it

Step 16: Old Power Supply

My old power supply its look like this but now i have my latest power supply.



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    22 Discussions

    It looks really ok ! Thank you for sharing !

    In the future, you could consider modding it; here are a few ideas(hope these will come in handy one day!):

    - Mains panel fuse. If it blows, you unscrew the cap, change it, screw it back.

    - The AC mains panel meter looks amazing, but you already know your mains voltage, my opinions is that you should save that meter for some future project. Replace it with an LED.

    - Turn it into an adjustable voltage/current power source. You just need a decent transformer, the circuit is quite easy to make. The transformer is the most important part of the power source.

    - If you`ll plan to turn it into an adjustable voltage/current power source, you should consider putting a voltage/current panel meter for the output.

    Hope this helped!

    Great instructable, by the way!

    10 replies

    You don't need to put a fuse if you use ATX Power Supplies, They already have some kind of electronic fuse

    Most ATX Power Supplies have the fuse soldered/in a holder inside. My idea was to mount a panel fuse holder, because it's so much easier to unscrew the cap, change it, screw the cap back on, then turn it on, rather than disassembling the whole thing, desoldering/changing the blown fuse, soldering back another one, then reassemble the PS back.

    This is how it looks like, by the way: https://media.perfprotech.com/media/products/lns-...

    Also, I don't know if you read a single bit of my comment, but I gave out some tips, for him to use in the future. Maybe he`ll do one from scratch, someday, using a transformer + rectifier + adjustable voltage regulator, and the fuse won't magically appear, u know.

    I thought that ATX power supplies have a fuse that protects against over current/short circuit, And only lets you power it up again if you unplug and re-plug it again...

    El-cheapo ATX Power Supplies have a fuse for mains voltage, on the pcb, soldered in most cases ( http://tr1.cbsistatic.com/hub/i/2015/06/03/2d0d28bf-098f-11e5-940f-14feb5cc3d2a/r00320010725vgl01_02.jpg )

    , a few Varistors-MOVs( https://en.wikipedia.org/wiki/Varistor ) and PTCs ( https://en.wikipedia.org/wiki/Resettable_fuse ). If they're super el-cheapo no-name brands, they always skimp on quality, and sell you a good working unit, but you don't want to be anywhere around that when your power surges. Protection is one of the key features of any electrical/electronic device.

    Also, keep in mind that it's better to have a fuse holder for your mains voltage fuse on the back of your bench power supply, rather than inside the case.

    Just to thank you for a good explanation. With a good explanation i can make a choice and take action.Thank you again for sharing your knowledge and being nice about it. Marie

    MarieS36 just follow me or broadcast my project and check out my new project

    Marie just follow me or broadcast my project and check out my new project

    I think Mr. ANDREINOUR is right For his modifying ideas.... AND THE MOST IMPORTENT IS TRANSFORMER...!!!!



    2. ON IT AGAIN



    2 years ago

    couldn't you just use the 5 volt output from the computer psu for the USB charger?

    1 reply

    I would suggest using a USB hub and using the 5v output to power it making the useful for data transfer as well as charging.

    I like it but a suggestion to add more ground posts. if you are working on a circuit needing multiple voltages you only have one common terminal... could get crowded there.

    Thank god... I thought I was the only one that signed my designs/concepts