Ferrite Chatter Noise

chatter teeth

GOT DC Cable Chatter?

Did you install snap on ferrite beads on each individual cable as shown below?  If you did and your snap on beads are vibrating (or chattering like the wind up teeth shown to the left), then you need to rethink your installation!

The dc current through the cable wound on your ferrites is inducing a field into the ferrite bead and the two separate ferrite parts are trying to complete the circuit and will “chatter” or vibrate.  If you are on a boat and flip on the battery charger/inverter which has the ferrites installed individually on the DC cable (+) and (-), you may hear the chattering all over the boat and this noise can drive you nuts!  Best to take off the ferrites and install both the red(+) and black (-) wires through the same ferrite so their fields cancel each other and the ferrites only have to suppress the common mode current on both cables (much smaller current field).

IMPROPER INSTALLATION (FSB31-1 shown)

Wrong Way

PROPER INSTALLATION (FSB31-1 shown)

FSB31-1 DC Noise Filter

If you are using larger cable, then you may need a large ring toroid (part # F400-31 – 4″ OD, 3″ ID) for installation as shown below:

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