Abstract: A portable charger includes a hand crank power generator adapted for generating an AC current and a DC conversion arrangement including an excitation rectifier electrically connecting to the hand crank power generator for rectifying the AC current to an undulate sine wave DC current, an oscillator circuit converting the undulate sine wave DC current into an undulate square wave DC current, a ballast filter circuit modifying the undulate square wave DC current to minimize a ripple thereof so as to form a modified square wave DC, a voltage regulator regulating the modified square wave DC to the stable DC current at an operation voltage, and a pulse DC current generator generating a short pulse-width DC current for allowing the stable DC current to power up the electric appliance.