In this era everything is getting smaller but bench power supplies can get big and in no way are they portable so in this instructable I am going to show you how you can make a power supply that is probably smaller than you phone and you can carry it anywhere you go.You could either use the internal batteries or even connect it to an external power source (up to 100 that's what i tried) for more power. The on board voltmeter makes the job even easier and the 4 different fixed voltages make the operation a breeze. So lets get started.
PLEASE TAKE A MOMENT AND VOTE FOR ME
Step 1: WHAT IS a POWER SUPPLY AND HOW IS THIS DIFFERENT
Power is a key component when working with electronics.However small a circuit be it will require a power source. So basically a power supply is what does the job.instead of having separate adapters or batteries for each project a power supply can give out multiple voltages, usually controlled with a regulator, and show it on a screen for easy use.This power supply is small thus perfect for small setups or on the go and can easily be made under 10$ or 600 Indian rupees.this power supply has 4 potentiometers or regulators for 4 fixed voltages and a bigger and easy to use regulator for a variable power source. the built in battery makes for power supply in case if you don't have a wall outlet around.
Step 2: HOW TO USE a POWER SUPPLY
In general power supplies have a regulator with some kind of display to show the voltage (and some time the amperage also)but this power supply is different,there are 5 switches 4 of which have a trimmer beside them. Each of the switches is for specific voltage and the first one for the variable one.
In simple words if i turn on any of the 4 switches with the trimmers a voltage specific to that switch will be gin out where as if I switch on the first switch the regulator gets engaged and a voltage that can be varied by the regulator id outputted.
Step 3: MATERIALS AND TOOLS
You would require the following parts to build the power
1. 9v battery and external power source
2. Voltage regulator – I have used a lm2596((buy here) as if deliver up to 3 amps ) based voltage regulator module but you can use an lm317((buy here)which can be made easily and I will explain it in a further step)
3. A enclosure to make the build look good – I used a small plastic box but one can use anything from cardboard to custom CNC box.(would be good to see a phone shaped box)
4. A SPDT center off switch or DPDT switch - make sure it can handle the power coming out of the power supply
5. A panel mount voltmeter (buy here)though this is extra and not required it adds a lot of convenience
6. Alligator clips – completely optional
7. Banana clips to make a swapable connection point
8.switches small 5 in number
9. Potentiometer -a big one with a knob would be good and 4 trimmer pots or the smaller variant all 10k ohms
The tools you will require apart from the basics like a screwdriver are
1. Soldering iron (with solder)
2. Dremel or any other rotary tool –optional
5.Hot glue gun
an hour or two depending on your experience and how elaborate you make the build
Step 4: PUTTING IN ALL THE COMPONENTS
First step would be to decide where everything goes, as this is a very compact build planning is crucial ,after you have marked the holes and finalized upon the design move on to cut holes for the various components.
After you are done with cutting holes stick the switches and pots as shown.
Use hot glue to hold everything but check once more for possible mistakes. If some parts have hard to reach contacts solder wires to them first.
Step 5: PREPARE THE VOLTAGE REGULATOR
In this step ,assuming you have a ready made voltage regulator or have made on referring to the circuit diagram given in the pictures, desolder the on board pot and check for the two pins which are connected with a multimeter or continuity tester.
Next connect one terminal of all switches to the respective pots,and the other pin gets connected to the voltage regulator board. The second pin of the pot also connects to the other pin on the voltage regulator board .
You can follow the schematic diagram.
Step 6: THE LAST CONNECTIONS
The connections remaining are that of the switches and the power sources.
To start off first connect the banana clips to the output of the voltage regulator.
for the voltmeter connect the positive wire to the input of the voltage regulator and the negative to the ground.
The remaining sense wire goes to the positive terminal of the output.
The switch can be wired by connecting the center terminal to the positive input of the voltage regulator(marked as A in the diagram). One of the other terminals goes to the positive of the battery and the other one to the positive of the external power source.
The remaining ground or negative wires can directly be connected to ground.
Step 7: JUST DONE...FINISHING UP
Check all your connections for solder bridges or short circuits with a multimeter and then finally close the project after connecting in the battery.
With all the small voltage regulator switches off turn on the main power switch, on one side it will work on the internal battery and on the other the external power source.
Step 8: TROUBLESHOOTING
If the previous step didn't work out then you might have made some mistake. Check all switches and power sources for shorts and even then if you are not able to achieve success do comment down below any queries if any.