Are you an old Nokia phone user? Ever envied of those smart phone users, who charge there device using USB? Technically it's possible for us to build USB charger for our mobile.
Most of the Nokia mobile use variant of BL-5C battery, so single universal charger can charger all the device. Nokia provide different charger based on the load. AC-11, AC-305, ... all of them have same output voltage rating with different current rating. Higher the output current, quicker the charging. So High end mobiles are provided with, high current charger and low end mobile with less current.
USB 2.0/3.0 have 2 power lines in addition to 2 data lines. USB 2.0 can provide power at 5V, 100mA to 500mA. This power is enough to charger mobiles.
Pin 1 & 4 are power lines and 2 & 3 are data lines. When data lines are open USB will provide 100mA current, when it is shorted will give 500mA current.
100mA is very less and it will take long time to charge, so let us fix our current requirement to 500mA by shorting the data liens (Pin 2 and 3).
- Get USB cable from local computer shop or take one from the old damaged mouse.
- As precaution measure the voltage across the pin 1 and 4 and confirm the polarity.
- Get charger pin or Take from old mobile.
- Connect USB pin 1 to inner ring of the charger pin
- Connect USB pin 4 to outer ring of the charger pin
- Short ping 2 and 3 to get 500mA current.
- Finally verification once by checking the voltage across inner and outer ring of the charger pin.
USB charger for your phone is ready. Happy Charging !!!