Introduction: World's Smallest DIY Pocket Power Supply
Power Supply is a fundamental device in any electronics lab . The major downside to them is that they are often bulky and are not very portable. if you want just a variable voltage output with step down voltage these big supplies don't make sense.So, Here I present you World's Smallest DIY Pocket Power Supply.This Supply is so small that it fits any one's pocket and is capable of many functions.
Also Check My blog for more :- http://hardiqv.blogspot.com/
Step 1: Features and Specs
This Pocket Power Supply has Following Features:-
- LED Display For Displaying voltage output .
- Output Voltage range from 2.5 v to 30 v.
- Input Voltage range from 5 v to 35 v.
- Output Current has high as 2.2 to 2.5 amp.
- No need of Heat sink.
- Very small fits in any pocket.
- Has variable output voltage.
- Voltage can be adjusted through a potentiometer.
- Terminal blocks for easy connection.
- feedback controlled ic
know more about IC here :- http://shink.in/fCQRX
Step 2: Gather Your Parts
Following parts are Required:-
- LM317T X 1
- 10uf/63v capacitor X 2
- 1N4007 diode or m7 diode(smd) X 1
- Terminal block X 2
- Led voltmeter X 1
- M3 bolts X 2
- small piece of perfboard or veroboard.
- potentiometer 5k ohm X 1
- BD139 transistor X 2
- Some wire
- 3d Printer
- Soldering Iron
- Lots of patience !!!
Step 3: Build the Circuit
I have attached the schematic of the power supply . download and print it if possible to avoid any mistakes.
I have also attached the step by step building photos . So make sure you follow them so that it becomes easy for use.
soldering the transistor is tricky as we are backpacking each other .
Tip :- placing the transistors in some sort of vice will help to solder very easily.
The voltmeter that i purchased was having the wires soldered very badly.
So, I removed them and then soldered it with a clean solder joint.
Make sure that the transistor and LM317T ic are flush with PCB.
Attachments
Step 4: Cleaning the PCB
After you have succesfully build your PCB as per the schematic then You may need to remove the PCB from the Veroboard.
For this I used DREMEL but you can use any rotary tool or you can the PCB to size before hand.
To avoid copper particles going inside the circuit I covered the entire circuit with Cello Tape. So that short Circuit is prevented.
After the cutting the PCB to use a blower or good blow from your mouth to blow off any copper bits .
Remove the cello tape and then inspect the circuit visually.
The Power supply will ready to be used now and will work flawlessly.
But I Designed and 3d printed the case to provide it more strength and rigidity.
So stick Around.
Step 5: 3D Designing and Printing
To provide a strength and good looks a 3D printed case is a must.
I designed my case in Fusion 360. and It is a two part Design
For 3D printing I used simplify3D to slice the model and then used my Anet A8 3D printer to print It.
You will need to M3 Bolts to join the two parts together.
Step 6: Finish and Demo
Here is the video Showing It in action.
So there You have it World's Smallest DIY Power Supply
I hope You liked This Instructable . If So, please considering Voting For me in the contest.

Participated in the
Power Supply Contest

Participated in the
Makerspace Contest 2017
6 Comments
5 years ago
And mine is ADJUSTABLE with a capacitor as a rotary knob.
And what do have to say?
WannaDuino STYLE.
Reply 5 years ago
Great build !! Congrats
Reply 5 years ago
Thanx,
Not the answer i was expecting! but oke.
WannaDuino.
5 years ago
Not a PSU but a regulator, in PSU there is "power" !
Reply 5 years ago
Exact master Rafununu.
As always you are 100% right.
WannaDuino.
Reply 5 years ago
You said it right . You may call it as a power supply in generally . But technically it is a regulator