maintains power between the ac supply and light circuit 160 power switch 280 is composed of a plurality of semi conductor switches one switch for each of the plurality of taps in autotransformer 250 in accordance with the principles of the invention upon the application of power by pass relay 230 is initially operational to provide the full input voltage to light circuit 160 phase detector 240 also initiates processes to analyze both the supply side power condition and the load side power condition controller 270 further positions auxiliary relay 220 to provide an electrical path through the dimmer circuit to light fixture 160 when phase detector 240 determines that the phase relation between voltage and current are within acceptable tolerance levels an indicator is provided to controller 270 which causes auxiliary relay 220 to close and provide the full input voltage to light circuit 160 thus both by pass relay 230 and auxiliary relay 220 are connected in parallel and each provides the a voltage level to light circuit 160 the system then checks the voltage output level and causes bypass relay 230 to open thus the voltage to light fixture 160 is smoothly transferred through auxiliary relay 220 and the dimmer circuit controls the electrical flow to light circuit 160 through by pass relay 230 auxiliary relay 220 is thereafter released when a light dimming request is detected then phase detector 240 determines whether the phases of voltage and current are within acceptable tolerance limits and provides an indicator to controller 270 controller 270 responsive to the indicator provided then progressively selects voltages from different tap settings of autotransformer 250 until.