Generally we have seen cell phone chargers in the form of small mains operated plug-in type adapters normally used in homes for charging a cell phone from the available AC outlets.
However these units are completely useless in places where AC mains outlets are not accessible or out of reach. At times we may find ourselves in such disconcerting situations especially outdoors with our cell phone showing a single battery indicator bar - gasping for power. Amidst a long travel course and with AC power nowhere the situation can definitely become grim and helpless.
The present Circuit is ideally suitable for
The diagram shows the connection layout which can be simply made over a general purpose PCB by soldering the relevant leads of the parts appropriately.
The testing is also very simple, after building the circuit, an input from a 12 volt battery may be given to the circuit with its output plugged in to a cell phone through a relevant pin. If everything is done correctly, you will find your cell phone readily accepting the charge and getting charged within an hour or so.