T25*15*13 Toroidal Wirewound Inductors
The design of power filter can be considered from common mode and differential mode. The most important part of the common mode filter is the common mode choke. Compared with the differential mode choke, a significant advantage of the common mode choke is its high inductance value and small volume. An important problem to be considered when designing the common mode choke is its leakage inductance, that is, the differential mode inductance. Usually, the leakage inductance is calculated by assuming that it is 1% of the common mode inductance, in fact, the leakage inductance is between 0.5% and 4% of the common mode inductance. When designing chokes with optimal performance, the effect of this error may not be ignored.
How does leakage develop? A tightly wound, fully wound loop, even without a magnetic core, has all its magnetic flux concentrated in the "core" of the coil. However, if the loop is not fully wound, or not tightly wound, then the…