PHD series are made by special FeSi powder. It doesn't include any adhesive, no aging. So alloy has a higher continuous operating temperature (155íµ). 1ú¼ PHD-40 can be used in medium frequency (4mm) Big size powder core >4 inch (OD) FeSi6.5% /HIGH FLUX 26ª¦ powder core: 1. Lower loss (Nearly zero gaps with reduction in fringe flux and core loss). 2. Lower temperature. 3. Lower cost 4. No noise 5. No aging. 6. Better temperature stability 7. Lower 30% weight and volume and easier to wind technical than big size powder core. PHD-60 VS Amorphous laminations with gaps(1MM4 inch FeSi6.5% / HIGH FLUX 60ª¦ powder core 1. Lower cost 2. Lower loss (Nearly zero gaps with reduction in fringe flux and core loss). 3. No noise 4. No aging . 5.Better temperature stability 6. Lower 30% weight and volume and easier to wind technical than big size powder core.