We believe that many people are familiar with common mode inductors, but do you understand the common mode inductor connection circuit? Regardless of the right common-mode inductance for your circuit? First of all, we need to understand the common mode inductance.
Common mode inductors are common mode interference suppression devices with ferrite as the core. It consists of two coils of the same size and number of turns symmetrically wound around the same ferrite ring core to form a four-terminal device. Common-mode inductors act as impedance in AC currents. For plug-in inductors, we usually see more UU and EE types as well as toroids.
When the AC frequency is fixed when the common mode inductor is connected to the circuit, the larger the inductance, the stronger the blocking ability of the AC current. On the contrary, the inductance is small, and the blocking ability is also small. It suppresses the common-mode signal in the circuit, and the inductance value of the common-mode inductance can be measured through the bridge.
Secondly, the application of common-mode inductor connection circuit in the common-mode inductor of switching power supply.
Common mode inductors are sometimes called common mode chokes, because it is a power circuit filter that plays a role in suppression, and is composed of various filters in the switch EMI, electromagnetic suppression of various high-speed signals generated by the outward emission, as shown in the figure, the circuit has more than one set of parallel wires, and the normal signal passage time is basically not affected, but when the common mode current flows, due to the isotropy of the common mode current, a magnetic field will be generated in the same direction in the coil and increase the inductance of the coil, and the coil performance is high impedance, A strong damping effect is generated, and the common mode current is attenuated, interfering with the purpose of suppression.
Thirdly, common-mode inductance connection circuits are widely used in automotive electronics.
Many circuits in automotive electronics are connected using common-mode inductors, such as engine control circuits, ABS anti-lock braking systems, airbag systems, etc. Common mode inductors play a role in suppressing electromagnetic interference in these circuits, improving the reliability and stability of the circuit. In automotive electronics, the performance requirements of common-mode inductors are very high, and they need to have the characteristics of high temperature resistance, low noise, and high stability.