Hi all. I am working on a inductor for a boost PFC controller. How do I calculate what the flux density in the core will be , to make sure I avoid saturation. The frequency will be 100Khz. Power level would be 300W. AC is 220V. The formula for flux density is B = (E* 10^8) / 4.44.N.A.F The value of 4.44 I assume I would change to 4.0 for a square wave , as the inductor is bieng switched at 100khz. The core I have is an MPP core (CM400060) with a Ae of 1.07cm^2 which I assume is A. What value should I use for E. Would it be 220 * 1.414 ? Say there are 105 turns on the toroid. That would give me a value of 690 odd gauss (69mT ?) . Does this look correct? According to the litrature I have , the MPP cores saturation flux density is about 8000 gause(0.8T). If my calculations are correct this core is WAY over spec , and I should be able to reduce it significantly , but I'm sure I'm missing something here.I would like to use a powder iron core as this is cheaper. Any help appreciated. Cheers Rob
- posted
18 years ago