TTC-4111

Common Mode Chokes (CMCs) are electromagnetic components that are used in power electronic systems to reduce unwanted variation in voltage across sensitive components. The TTC-4111 is a particularly useful example of a CMC, composed of two symmetrical windings, with cores of magnetic (ferrite) material and two separate windings for the common mode and differential mode. This allows the device to respond to both common and differential mode currents. The TTC-4111 is suitable for reducing the level of common mode voltage or harmonic distortion in the power electronic system in which it is implemented.

The working principle of the TTC-4111 can be divided into two categories: the common mode filtering and the differential mode filtering. The common mode filter (CMC) works by creating a magnetic field, which opposes the changes in voltage. The magnetic field is created as a result of currents in the winding, with the same direction of the induced magnetic field. The magnitude of the magnetic field is determined by the number of turns of the coil and the current flowing through it. The magnitude of the voltage across the component then decreases due to the opposition of the magnetic field created by the CMC.

The differential mode operation of the CMC is based on the principle of inductive coupling. This type of filter works by forming an inductive link between two circuits, with the direction of the coupling depending on the direction of the current flowing through them. For example, when a voltage appears across one of the windings, it induces a current in the other winding. The magnitude of the induced current is proportional to the magnitude of the voltage; that is, larger voltage will induce larger currents. This current then opposes the original voltage, reducing the net voltage across the component.

The application field of the CMC is wide, including power electronic systems such as motor drives, switch mode power supplies, battery chargers and solar panels. In motor drives, CMCs are used to reduce the magnitude of the common mode and differential mode voltages, thus preventing motor damage and instability. Likewise in switch mode power supplies, CMCs can be used to reduce voltage and current spikes, reduce electromagnetic interference, and lower emission levels. Battery chargers also commonly use CMCs to reduce the level of ripple and echo phenomena presented by the battery. Finally, solar panels can also benefit from the use of CMCs, by reducing and controlling voltage peaks and preventing saturation of the inverter transformer in the system.