40 uH DC Servo EMI Filter for Gecko Drives


Available Now

This is a simple passive EMI filter for brushed DC servo motors and the Gecko 320 / Gecko 320X servo drivers. If your control system has noise problems that cause a touch probe or end switches to falsely trigger installing these can help reduce some of the noise.

EMI Filter


The filter is designed to the specification of the Gecko 320 datashheet. See the article on reducing rf interference

The coils are 40uH. The board is designed for 15A and has 2mm electrical spacing. Weighs 6.5 oz.


Simply wire the filter between the + and - armature coils. The filter comes with pluggable connectors making it easier to install.

The following scope screenshots show with and without the filter on a 24V brushed dc servo motor.

Without the filter

Without filter

Without the filter the scope triggers at a much lower level with peak to peak noise around 16V.

With the filter

With filter

With the filter at the same settings the scope shows a peak to peak voltage of 700mV.

The FFT shows it smooths out the low frequency noise significantly..


There are 4 x M5 mounting holes spaced 2.36" by 1.22" (60 mm x 31 mm). The dimensions are approximately 3" by 1.75" (74 mm x 42 mm)