A power converter with a feedback controller includes a converter body with an input end for an input voltage, an output end for an output voltage, a controller with a feedback device, and a connector for connection with the output end of the converter body and with an electric appliance. The circuit of the converter body converts an input voltage to an output voltage. A controller is connected in circuit to the converter body and includes a circuit for regulating the voltage for a desired system output. The feedback device connects to the output end of the converter body. The output voltage is adjustable only when the controller receives an output voltage as a feedback from the feedback device. The controller is not triggered and hence an output voltage is not adjustable when the connector is engaged with the output end of the converter body.