It is a simple mini power bank. You can use this power bank at the time of any emergency. This power bank is operated by a 9 volt battery along with the voltage regulator- LM7805 which produces and output of 5V. This project is very easy to make, costs less than a 100 Rupees (less than a dollar) and you will also able to learn the use of volatge regulators.
So, without wasting any time, get your things ready and PROJECT IT YOURSELF!
Step 1: THINGS REQUIRED
1. A 9V Battery Connector
2. A 9V Battery
3. Two cut outs of sunboard (dimensions w.r.t. the battery)
4. Mirco USB pin (cable)
5. A LM7805 IC
These all are the major things. Besides this, you also need some toolas like sciccors, cutters, glues etc.
Step 2: SETTING THE BASE FOR THE POWER BANK.
Take the sunboard cut outs and pierce two holes to place the battery cap.
Insert the wires of the battery cap and stick it with the super glue.
Note that correct posotion of the battery cap is necessary, so that all the components will be placed perfectly.
Step 3: PLACING THE MICRO USB
You can get the micro USB (suitable to your phone) from any old charger or OTG cable. Cut the micro USB part from the main part and remove the insulator part and cut the green and white part.
Glue the micro USB at the back side of the board with super glue.
Note that the Green and White wires of the cable are not meant for power sharing.
Step 4: PLACING THE IC
The IC is the most important part of this project. LM7805 is an Voltage Regulator which produces an output of +5V.
There are three pins in this IC:-
Pin 1 (Input Pin): The Input pin is the pin that accepts the incoming DC voltage, which the voltage regulator will eventually regulate down to 5 volts.
Pin 2 (Ground): Ground pin establishes the ground for the regulator.
Pin 3 (Output Pin): The Output pin is the regulated 5 volts DC.
Be advised, though, that though this voltage regulator can accept an input voltage of 36 volts, it is recommended to limit the voltage to 2-3 volts higher than the output regulated voltage.
The 05 (in LM7805) represents the voltage output, i.e. here 05 represents a voltage output of 5V.
Placing the IC
Place the IC opposite to the micro USB, just to save from the wires from being messy.
Join the wires as show in the picture no.3 i.e.
Pin 1: Input from battery(positive terminal).
Pin 2: Ground (Negative terminals of both battery and the micro USB cable).
Pin 3: Output (positive terminal of the micro USB cable).
After connections, solder all the wires and components and make sure that there is no chance of short circuiting.
Step 5: FINISHING THE PROJECT
At the last, cover the circuit with the sunboard and colour it (or tape it) with black. Make sure that all the connections are made properly.
after decorating, add the 9 volt battery and also tape it.
Take the Lili-Power Bank and connect to your phone.
You can see that in the photo that the Vivo phone is charging through the power bank.
Step 6: The LILI POWER BANK Is Ready.
YOUR LILI POWER BANK IS READY.
Now you can use this small, portable and simple power bank in your emergencies. Make sure that the input voltage of your phone is either 5V or less than that.