The board can be used in applications where dimming of 110-220V AC power is required like dimming of bulb or fan. The input can be simple 4 bit high/low signal from microcontroller working at 3V or 5V which is isolated with the use of opto-couplers. Total of 16 levels of power control can be set from totally off(0%) to full on(100%) as per input control levels.