Most of the Mobile phone batteries are rated at 3.6 V/500 mA. A single
pen torch cell can provide 1.5 volts and 1.5 Amps current. So if four
pen cells are connected serially, it will form a battery pack with 6
volt and 1.5 Amps current. When power is applied to the circuit through
S1, transistor T1 conducts and Green LED lights.
When T1 conducts T2 also conducts since its base becomes negative. Charging current flows from the collector of T1. To reduce the charging voltage to 4.7 volts, Zener diode ZD is used. The output gives 20 mA current for slow charging. If more current is required for fast charging, reduce the value of R4 to 47 ohms so that 80 mA current will be available. Points A and B are used to connect the charger with the mobile phone. Use suitable pins for this and connect with correct polarity.
When T1 conducts T2 also conducts since its base becomes negative. Charging current flows from the collector of T1. To reduce the charging voltage to 4.7 volts, Zener diode ZD is used. The output gives 20 mA current for slow charging. If more current is required for fast charging, reduce the value of R4 to 47 ohms so that 80 mA current will be available. Points A and B are used to connect the charger with the mobile phone. Use suitable pins for this and connect with correct polarity.
No comments:
Post a Comment