1. Common mode inductors and differential mode inductors

Common mode inductors and differential mode inductors are one of the effective anti-electromagnetic interference components, which are widely used in various filters, switching power supplies and other products , But the common mode inductor is used to suppress common mode interference, and the differential mode inductor is used to suppress differential mode interference, both of which are more important filter inductors.

Second, common mode inductance and difference Mode inductance identification

Although the two kinds of inductors are filter inductors, the different functions determine the appearance and winding method will be different. For common mode inductors, it is wound on the same core , And the coil diameter of the two windings is the same as the number of turns, but the winding direction is opposite. A set of coils has two pins, so the common mode inductor will have 4 pins; while the differential mode inductor is wound on a core There is only one coil, so it has only 2 pins, so common mode inductance and differential mode inductance can be distinguished from the number of pins.

Three, common mode inductance and differential mode inductance application

The following figure is a partial circuit diagram of an EMI filter circuit, where L1 is a common mode inductance, it has a total of 1-4 leads L2 and L3 are differential mode inductors. They have two pins 1-2 respectively. It can be seen that the differential mode inductor passes through the AC power current. This type of differential mode inductor can withstand large AC currents and generally appears in pairs.