The FS-1 filter is designed to reduce disturbances that occur, e.g. during operation of a relay or a contactor. Except RLC elements it also has a surge arrester with operating voltage of 1kV.

The filter can work with voltage of up to 250V AC or DC and maximum load current of up to 1A.

The FS-1 filter finds practical usage in output circuits of controllers as disturbances dampener that can cause incorrect operation of these controllers and it is usually installed in the circuit of relay contacts that controls the contactor’s coil.