Modern home and work environments are full of cables, and if you pick one up and inspect it, you’re sure to find a few mysterious bumps along the length of the line. Ever wondered what their function is? Well, these cubic structures are known as ferrites. And, no, their purpose is not merely decorative; rather, they play an instrumental role in preventing, or at least, limiting the disruptive effects of electromagnetic interference (EMI) on electronic devices. The problem is, all electronic items receive and transmit EMI, and cable ferrites isolate the circuits from interference. But there’s more to these small components than meets the eye, and we’ll explore four interesting facts about cable ferrites below:
The mixture of iron oxide and one or more metals produce a ceramic compound, which is used to produce ferrites. Their ability to safeguard sensitive electronic products from conductive transients has made them a mainstay in the shielding industry. And because they are simple enough to create but highly efficient in performance, ferrites are commonly used to protect electronic goods when plugged in.
Simplicity is the name of the game when it comes to cable ferrites. Installing them is a matter of mere minutes; all you have to do is click them around the cable that needs protection, and you’re good to go. No wonder cable ferrites have emerged as the leading shielding mechanism when it comes to everyday electronic goods, like charge controllers, computers, solar panels, laptops, amateur radios, and generators. However, keep in mind that cable ferrites are specially designed to protect sensitive gadgets from electromagnetic pulse or EMP, a kind of transient disturbance. So, choosing a random ferrite won’t work since they do not all possess the same properties.
Noise frequencies severely hamper electronic performance. For this reason, electrical engineers and designers have a few established parameters when it comes to choosing the right cable ferrite for their products:
- Manufacturers must ensure the availability of varying sizes of cable ferrites so that they can fit different types of cables snugly.
- The products must provide more than 1 GHz of broadband protection.
- The cable ferrites must have snap-on functions for smooth, hassle-free installation. Remember, the better the fit, the better the performance of the structure.
- The items must be available at a moderate cost.
- The ferrites must offer the highest possible resistance to suppress transients more effectively.
- The lengthier the design, the better. However, electrical engineers usually make it a point to avoid thicker cable ferrites
- The inside dimension of the cable ferrite must fit the outer dimension of the cables that are being shielded from receiving or emitting EMI.
- The bead must be surrounded by heat-shrink tubing, so it remains protected against the generated heat.
- When seeking cable ferrites for power application, select items with the greater cross-sectional area.
Ferrite bead performance relies greatly on the placement of the component. The closer it is to the EMI source, the more efficient it is at suppressing radiation. Moreover, nearby placement enables the beads to stop noise sources from coupling to more structures inside the product. However, since filtering features cannot be easily implemented for every aspect of the electronic gadget, preventing the noise source from coupling helps improve the effectiveness of EMI shielding. Keep in mind though, that if you plan on using cable ferrite beads on shielded enclosures, you must install it as close to the source of EMI as you can, preferably near the exit or entrance path of the cables in the shielded enclosure.
If you’re looking for a simple, no-fuss shielding solution, invest in cable ferrites. Despite their deceptively small size, these components are capable of handling an array of complicated tasks. But choose the right cable ferrite as per your needs, and trust your designers to point you in the direction of the best solution.