This project is the study about making the electrical voltage setting 0 – 220 Volts by software system with electrical voltage control of the auto transformer while it has 100 kv 10 kVA Especially the electrical voltage control has 65 ampares 0-220 volt 1 phase 50 Hz By the application of Visual Basic version 6 to the software and then use the micro controller in the board to control the stepper motor by setting the core of the auto transformer in the set of pattern while a computer is setting far away from the electrical High Voltage control and then it will apply the measurement system to the monitor display of software process system for development of software to the electrical Voltage section in the Electrical High voltage Lab to safety the danger of the test.