Mobile Phone Travel Charger
Here is an ideal Mobile charger using 1.5 volt pen cells to charge mobile phone while traveling. It can replenish cell phone battery three or four times in places where AC power is not available.
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.
Designed by D.Mohan kumar
about 4 weeks ago
Dear Sir,
I have assembled the circuit on General Purpose Board, its working fine with all the new type of mobile phones, but i am not able to charge the OLD i.e. 3310,1100, type of mobiles, i am using the battery SMF 6V1.2 Amp. please help me to charge my mobile phone 3310 with this type of charger.
indraneel
9623241611
about 4 weeks ago
See the rating of the Mobile battery.If is rated more than 3.6 volts,this design is not sufficient.Increase the input voltage to 9V or12V and use 7.2 or 9.2 volt zener.All the other parts remains same
about 3 weeks ago
I put the A and B point with the current meter. The R5 flow a 20mA(0.02A) at 6Volt supply. It is not 185mA(0.185A) but 20mA(0.02A). This is between A+ point and B point current without phone battery. I replace T1(BC548) and T2(Sk100) by T1(BC547) and T2(BD-140: medium PNP). Others are same parts. Would you tell me what is wrong?
about 3 weeks ago
Actually you are right, the maximum current that can flow is 20 mA, because R4+R5 = 270 + 27 = 297 and therefor 6V/297Ω = 0.02A ( U/R = I). So please, I am asking the author of this circuit to test it before publishing it.
about 3 weeks ago
What?
Is that really?
Oh my god!!!
about 3 weeks ago
The circuit is well tested.See the comment of Indraneel in the same page
about 3 weeks ago
There is an error in the write up.The circuit actually gives 20 mA current for slow charging the battery.60 to 80 mA current is safe for the battery to avoid heating up.If you want to increase current, reduce the value of R4 to 47 Ohms, so that 80 mA current will be obtained. BD 140 can pass more current than SK100. Experiment with the circuit and see the improvement
about 3 weeks ago
Sigh,
Thank You, D.MOHAN KUMAR.
I was broke this soldered circuit-board after reading your posting.
I will wait your simple and better working circuit.
Thank You.
about 3 weeks ago
We are posting better circuits after trying the circuits.Errors during posing will be edited at the moment we detect it.Thanks for your comments.Try it I am using the same circuit during journey