The invention discloses a multi-output multi-purpose power supply circuit capable of being fully charged, which comprises a mains supply, a step-down rectification filtering module, a switch module, an adjustable
voltage stabilization module, a
square wave output module, an oscillation starting module and a multi-power supply output module, and is characterized in that the mains supply is connected with the step-down rectification filtering module, the step-down rectification filtering module is connected with the switch module, the switch module is connected with the adjustable
voltage stabilization module, the adjustable
voltage stabilization module is connected with the
square wave output module and the oscillation starting module, the
square wave output module is connected with the oscillation starting module, and the oscillation starting module is connected with the multi-
power output module. The multi-output multi-purpose power supply circuit possesses beneficial effects that the multi-output multi-purpose power supply circuit can output a plurality of voltages for
electric equipment to use, when it is needed to charge a battery, the
potentiometer resistance value can be adjusted to change the duty ratio of square
waves output by a 555
timer, so that when the battery is charged, the battery can release charges accumulated on the positive
electrode of the battery, the charging effect is ensured, and the battery can be charged to a rated voltage.