Without any
USB to phone battery charger circuit we can
charging phone battery using port on USB computer , but it will quickly damage the phone battery, and the battery will bulge. Because the voltage which was issued on usb is 5 volts , while the average-voltage phone battery 3.5 - 3.7 volts. That's why this USB to phone battery charger circuit is required , this USB to
phone battery charger circuit reduce votlage to 3.7 volt usb, but will not reduce currents and will make a
durable phone battery.
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| USB to phone battery charger circuit diagrams |
List of components :
R1 : 1 K
R2 : 330 R
R3 : 4K7
R4 : 300 R
R5 : 27R
D1 : 4.7 volt zener /1W
C1 : 100uF/16V
Q1 : BC548
Q2 : BC558A
LED1 : Green Led
X1-1 : Vcc USB
X1-4 : Ground USB
X2-1 , X2-2 : To phone battery
See also this printed circuit board ( PCB ) of USB to phone battery charger :
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| USB to phone battery charger printed circuit board |
