mobile phone charging characteristic

hi everyone, i have a project which involve charging cell phone, therefore i would like to find out mobile phone internal charging characteristic.

I open up my cell phone charger and wat i saw is transformer and some rectifying circuit.

So what i would like to ask is , what will happen when the cellphone battery is fully charge?will the internal circuit in the cellhone limit the current which enters the phone?or the current will be continuosly provided until a person switches of the charger?

thanks for the reply

The charge regulator IC chip is built-into the phone. All the external charger does is is make DC. That way, you can charge in the car or at home.

Is the transformer large and heavy or it is a cutesy one? Modern ones equipped with power electronics is much better if you're considering to design one. The bulky transformers always get hot, I hate it.

Almost all cell phone chargers on modern cell phones are switching regulators, as mike said they're nothing more than power supplies, the phone itself handles the charging of the battery itself. So all you have to do is match the voltage output of the charger you currently have and be able to supply it's rated current. Since you already have a power adapter why do you want to make one?