Motor-side and input-side filters from FAULHABER

FAULHABER offers electronic filters for a wide range of requirements that are compatible with the DC motors and controllers from its product portfolio. The filters are divided into different functional and current ranges and are used wherever additional filtering is beneficial due to poor signal quality or existing or expected interference.

Depending on the application, motor-side filters are used between the controller and the motor in the motor phases, or input-side filters are used on the supply voltage side. The latter are particularly relevant when motor filters cannot be used or when their effect is not sufficient. Depending on the interference pattern and installation situation, the appropriate filter solution can be selected for the respective application.

Overview of filter types

Emission-reducing, ferrite-based motor filters

The EFC electronic filters are used on the motor side and reduce high-frequency coupling currents on the shield by reducing the rise time of the motor voltage/current. They require only three phase connections; a 0 V return line is not necessary. This makes them particularly suitable for applications in which high-frequency interference on the motor cable needs to be reduced. It is recommended to keep the connection cable between the Speed Controller or Motion Controller and the filter as short as possible.

Motor-side PWM filters

The motor filters of the EFM series remove the PWM from the motor cable by means of DC averaging. This reduces switching edges and specifically shifts interference to the input side. For the proper filter effect, all PWM filters require a 0 V connection, which should be connected as short as possible to the 0 V voltage (GND) of the motor supply. The EFM filters are designed for a maximum motor supply voltage with a nominal value of 50 V and for nominal motor currents of 1, 3 or 8 A, making them particularly suitable for high PWM frequencies.

Input-side filters

The EFS supply filters are intended for applications in which motor-side filters cannot be used, for example with integrated controllers, or where their filtering effect is not sufficient. They act on the supply voltage side and remove interference from switching regulators as well as part of the motor interference on DC networks. This makes these filters particularly suitable for applications with increased requirements for interference immunity and EMC.