A power supply system for controlling the drive voltages applied to a thin film electroluminescent (TFEL) display panel is disclosed. The system includes a power supply that generates the drive voltages to the TFEL display panel and causes it to emit light. A replaceable or resettable display voltage memory located adjacent the display panel provides the power supply with voltage information specific to the display panel. A feedback circuit measures the light emitted from the display panel. A balancing circuit controls multiple display voltages so that they have the proper relationship with respect to each other. The information from the display voltage memory and the feedback circuit is used by the power supply to control the output of the display voltages.