## ESD-R-47 Series: EMI Round Ferrite Cores The **ESD-R-47** is a specific model of round ferrite core manufactured by **KEMET**. These components are passive electronic parts designed to suppress electromagnetic interference (EMI) and noise in electrical circuits. --- ### 1. Technical Specifications The "47" in the series name typically refers to the outer diameter or a specific dimensional casing size within the KEMET catalog. | Feature | Description | | :--- | :--- | | **Material** | Manganese Zinc (MnZn) or Nickel Zinc (NiZn) | | **Shape** | Toroidal / Round Ring | | **Function** | EMI / RFI Suppression | | **Impedance Range** | High frequency noise absorption | | **Operating Temp** | Typically up to +120°C | --- ### 2. Core Material Comparison The ESD-R series uses different materials depending on the frequency of the noise being targeted: * **MnZn (Manganese Zinc):** Best for lower frequency ranges (kHz to low MHz). It has higher permeability. * **NiZn (Nickel Zinc):** Best for higher frequency ranges (MHz range). It has lower permeability but higher resistivity. --- ### 3. Key Applications These parts are used as "chokes" or "beads" to clean up signals in the following scenarios: 1. **Consumer Electronics:** Used on power cords or internal wiring of TVs and gaming consoles. 2. **Industrial Equipment:** Preventing noise from motors or power supplies from interfering with control logic. 3. **Data Communications:** Shielding high-speed data lines from crosstalk. 4. **Medical Devices:** Ensuring high signal integrity in sensitive diagnostic tools. --- ### 4. Installation Method The ESD-R-47 is a **solid core**, meaning it is not a "snap-on" type. To use it: 1. The wire or cable must be threaded through the center hole before the connector is attached. 2. For increased impedance (better noise filtering), the wire can be looped through the core multiple times ($N^2$ rule: doubling the turns quadruples the impedance). --- ### 5. Part Number Breakdown (Example) `ESD-R-47D-1` * **ESD:** EMI Core Series. * **R:** Round shape. * **47:** Size code (Outer Diameter). * **D:** Specific material/coating characteristic. ---