Hi, I need an SMPS for a dynamic load. (24V - 8A PWM 1kHz) I used several supplies and i noticed most of them make a buzzing sound. The feedback-loops in the supplies seem to be too slow so the SMPS goes oscillating. At some loads the SMPS sounds very odd, like it is gonna die... Only an SMPS without a Power Factor Corrector seems to work fine, no buzzing at all! (Meanwell S-240-24) At 200W it is necessary to have a PFC, i believe. Anyone an idea what i can do??? Thanks!