A variable output module provides accurate full range dimming or adjustment of power output. The variable output module utilizes the characteristics of an AC or other periodic signal rather than its power output to accurately determine the level of dimming a user desires. In this manner, the variable output module provides accurate full range dimming without the need for calibration to specific AC signals. The variable output module can detect the period of an AC signal allowing the driver to be used with various frequencies without the need for calibration. In one or more embodiments, the driver compares the pulse widths of a dimmed AC signal to the period of the AC signal to determine the desired level of dimming.