Mean well 40w single output switching dimmable led power supply lpf 40d series mean well lpf 40d 12 the mean well lpf 40d 12 is a 4008w single output switching dimmable led power supply from the lpf 40d series this led power supply features a wide input range of 90 to 305v ac a built in active pfc function and is equipped with a three in one dimming function with the psus design flexibility it is possible using 1 to 10vdc pwm signal or by changing resistance to achieve brightness red