I have a cell phone charger that no longer works and therefore I do not use it anymore. Can I turn this charger into a power source?
Mobile phone chargers are designed specifically for this function, having intelligent circuits that control the current in the charge (battery on charge) and detect when it is charged. Thus, they do not provide a constant current or a fixed voltage. In addition, they have circuits that operate without insulation from the power grid. For this reason, they are not used to power any other appliance, being used as power supplies. One can try to raise and its circuit and from it make the proper modifications, but would be a laborious process that would come out more expensive than buying a source.