rkarlqu@hpscdc.HP.COM (Rick Karlquist) (05/06/89)
I notice in ferrite core catalogs that core loss (for a fixed value of B) is always approximately proportional to switching frequency squared. Assuming that the dominant loss mechanism is hysteresis, it seems to me that each time you go around the B-H hysteresis loop you give up a certain amount of energy. In fact, the number of joules of energy is equal to the area of the B-H curve. If you double the frequency, you go around the curve twice as many times per second resulting in twice as much energy lost per second. Since power is energy per second, twice as much core loss power should be expended (not four times as much). Where is my thinking wrong here?: a. Hysteresis is *not* the dominant loss mechanism (?) b. The B-H loop gets bigger if you traverse it more quickly (?) c. Some other misconception Rick Karlquist HP Santa Clara