This is a hobby project which can be made by anyone following some very simple instructions. The charger works by reducing the voltage of the 4x1.5V AA batteries to 5V using a voltage regulator IC 7805 since the voltage required by a phone is 5V for charging.
Step 1: Items Required
3. Voltage regulator IC 7805: This will give you constant output voltage, doesn't matter what the input voltage is. (Available here: https://goo.gl/kcySDH)
4. USB A-Male to Micro B Cable: The micro end is required to connect the phone to the mini power bank. (Available here: https://goo.gl/kcySDH) )
5. Glue Gun (Available here: https://goo.gl/kcySDH) )
Step 2: How It Works?
When 4x1.5V batteries are connected in series connection the total voltage is 4X1.5V= 6V which is above the save limit of the phones and therefore cannot be connected directly to a phone for the purpose of charging. Thus an IC 7805 is used to regulate the voltage and to make sure that we have a constant 5V output.
The following are the steps to be followed:
1. Cut out the micro end of the USB cable and clip of the data cables. (We require only RED and BLACK wires)
2. Now using a solder iron make the following connections as given below :
3. Paste the IC 7805 on the battery holder using a glue gun so as to secure it on the surface.
4. Install four AA size batteries in the battery holder (Make sure they are charged)
5. Bingo! now you are ready to test your ‘Emergency Mobile Charger’