This paper presents the development of a fuzzy controller for a synchronous generator by means of the exciter, fed by a voltage converter (DC/DC), controlled by pulse width modulation (PWM). The transfer function of the generator based on the data of the input voltages of the exciter and generator output voltage is determined; these data were obtained experimentally. Card data acquisition NI USB-6009* is used for communication with Matlab Simulink** and the implementation of the Fuzzy controller; the output of the controller closes the control loop voltage through port A of microcontroller PIC18F452***. The control system is based on voltage level comparison rule, which is injected into the exciter by means of a variable voltage source that depends on the load connected to the generator output.