cellphone charger circuit

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Wew! I understand. Thanks.

Though a few more questions. Which is doing the control for the charging whenever the battery is full, the cellphone or the charger itself? It baffles me but my bet is the cellphone.

I really forgot on how to determine the time it takes for a specific charger to full charge a cellphone. Do you know how? Like 5v .07A with a cellphone battery of 3.7v 950mA
 

What you are making in this case is just a power supply for the internal charger so every aspect of the charge is going to be controlled by the charger circuit which is inside the phone.

If the charge was using constant current then you could get a result just by dividing the capacity of the battery with the current value , for example if you charge with a constant current of 1A then a 5AH battery needs 5 hours but in the lithium battery case you are only charging with a constant current in the first stage, then the charging continuous with constant voltage until the current drops to very low levels.
I don't have a calculation for that type of charge.
 

Electronic parts like a 7805 voltage regulator IC have a guaranteed maximum output current of 1A, a typical max output current of about 2.1A and a max output currentof 2.4A.

A cell phone has a charger circuit inside that applies the correct amount of voltage and current to the Lithium battery in the phone.
The "charger" for a cell phone is simply a 5V power supply that powers the charger circuit in the phone and also might power the phone while its battery is charging.
 

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