Voltage transformer with sequentially switchable voltage selection circuit

A voltage transformer with a sequentially switchable voltage selection circuit for converting the voltage value of input electrical energy into one of a plurality of predetermined output voltage values and outputting the electrical energy, comprising:

• a body, which is formed with at least one socket portion, and has an input port for receiving the input electrical energy and an output port for outputting output electrical energy having one of the plurality of predetermined output voltage values;
• a connection device for correspondingly plugging in the socket portion;
• a sequentially switchable voltage selection circuit, which is arranged within the body with its two ends electrically connected to the input port and output port respectively, including
• a voltage transformation unit;
• and
• a micro control unit, which is electrically connected to the voltage transformation unit and the socket portion, and has a clock generator for generating a clock signal that enables a sequential change in a voltage value sent to the voltage transformation unit when the connection device is plugged in the socket portion;
• and
• a display device for displaying the voltage value of the electrical energy outputted from the output port.