# Learning Electronics

Learn to build electronic circuits

# Mobile Phone and iPod Battery Charger Circuit

Charge your iPod without connecting it to a computer!

Using the USB port on your computer to charge your player’s batteries is not always practical. What if you do not have a computer available at the time or if you do not want to power up a computer just for charging? Or what if you are traveling? Chargers for Mobile Phones iPods and MP3 players are available but they are expensive and you need separate models for charging at home and in the car.

This charger can be used virtually anywhere. While we call the unit a charger, it really is nothing more than a 5V supply that has a USB outlet. The actual charging circuit is incorporated within the iPOD or MP3 player itself, which only requires a 5V supply. As well as charging, this supply can run USB-powered accessories such as reading lights, fans and chargers, particularly for mobile phones.

The supply is housed in a small plastic case with a DC input socket at one end and a USB type "A" outlet at the other end, for connecting to Mobile Phone, an iPod or MP3 player when charging. A LED shows when power is available at the USB socket. Maximum current output is 660mA, more than adequate to run any USB-powered accessory.

Pictures, PCB and Circuit Diagram:

Parts:

P1 = 1K
R1 = 1R-0.5W
R2 = 1R-0.5W
R3 = 1R-0.5W
R4 = 1K
R5 = 560R
R6 = 10R-0.5W
R7 = 470R
C1 = 470uF-25V
C2 = 100nF-63V
C3 = 470pF
C4 = 100uF-25V
D1 = 1N5404
D2 = 1N4001
D3 = 1N5819
D4 = 5.1V-1W Zener Diode
D5 = 5mm. Red LED
L1 = 220uH
S1 = USB 'A' Type Socket
SW1 = On/Off Switch
IC1 = MC34063A

Specifications:

Output voltage ----------------------5V
Output current ---------------------660mA maximum for 5V out
Input voltage range ------------------9.5V to 15V DC
Input current requirement ----------500mA for 9V in, 350mA for >12V input
Input current with output shorted--- 120mA at 9V in, 80mA at 15V in
Output ripple ------------------------14mV (from no load to 660mA)