Current transformer manufacturers, the function and working principle of common-mode inductor
The role of a, common-mode inductor, principle believe for common-mode inductor a lot of people are not unfamiliar, but for its connection whether you fully understand?
Your electricity is connect to the common-mode inductor on the road?
We begin by identifying the common-mode inductor.
Common-mode inductor with a ferrite core of common-mode interference suppression devices, it is made up of two sizes of the same number of turns and coil symmetrically on the same ferrite ring core, forming a four terminal device, common-mode inductor current obstacles role on communication.
For a plug-in inductor, we usually see more is UU type and EE type and ring type, etc.
Certain circumstances, the alternating current frequency inductance is larger, the impediment to alternating current (ac) ability, the greater the small inductance its blocking ability also to the contrary, it's on the inhibition of circuit is a common mode signal, common-mode inductance of the inductor value can use a bridge to measure.
2, common-mode inductor in the application of switch power supply common-mode inductor is sometimes also called common-mode choke coil, because it is used as controls, more used in switching power supply circuit, a various of EMI filter for filtering, inhibition of high-speed signal of electromagnetic wave to launch, as the chart, circuit has a set of parallel lines, the normal signal basic is not affected by time, but when have the common-mode current flows through, as a result of the common-mode current ecotropic, would produce in the coil magnetic field direction and increase the coil impedance, the coil performance for high impedance, the stronger damping effect, this time the common-mode current will be attenuation, suppressing interference.
The following chart is the principle diagram of the front-end part of switch power supply, the L1 is common-mode inductor, in order to prevent the common-mode interference, we know that the common mode signal is equal amplitude and phase of the same signal, the noise it generates noise is over the ground, is two wires of the noise respectively, to understand the common mode noise we know common-mode inductor knew why common-mode inductor would meet on the ac side.