Ferrite Choke Bead

Ferrite choke basic filtering applications. 
5mm size 25*13mm suitable for 3.5-5mm cable
7mm size 30*16mm suitable for 5-7mm cable

How ferrites act as resistors at high frequencies, and how this is used for EMI/RFI Suppression, improved power supply filtering, parasitic oscillation suppression, and noise suppression. The affect of the frequency dependent resistive characteristic of the ferrite choke is demonstrated by showing its effect on a swept RF signal, its effect on the rise/fall time of a digital signal, and its effectiveness of eliminating parasitic oscillation.

A ferrite choke, or ferrite bead, is a simple hollow cylinder or bead that is made of ferrite material and that is used in order to suppress or filter the amount of high frequency electromagnetic interference (EMI) noise found in electronic circuits. Ferrite is a black semi-magnetic substance that is shaped like a cylinder and that consists of iron oxide along with a mixture of other metals. Ferrites are encased in rubber or plastic material to protect and keep the ferrite bead in place.