## ESD-R-47D-1: Technical Overview The **ESD-R-47D-1** is a high-performance **EMI (Electromagnetic Interference) core** manufactured by KEMET. It belongs to the ESD-R series, designed specifically for round cables to suppress high-frequency noise. ### 1. Component Identification | Property | Specification | | :--- | :--- | | **Manufacturer** | KEMET | | **Product Series** | ESD-R (Round Cable EMI Cores) | | **Material Type** | Manganese Zinc (MnZn) | | **Core Shape** | Toroidal (Ring) | | **Color** | Black (Uncoated) | --- ### 2. Physical Dimensions Precision is critical for fitting these cores over existing wiring harnesses. * **Outer Diameter (OD):** 47.0 mm * **Inner Diameter (ID):** 27.0 mm * **Height (H):** 15.0 mm ### 3. Technical Specifications The ESD-R-47D-1 is designed for effective noise attenuation in specific frequency bands. | Parameter | Value / Range | | :--- | :--- | | **Effective Frequency** | Low to Mid Frequency (Broadband suppression) | | **Operating Temperature** | -25°C to +85°C | | **Impedance @ 10 MHz** | ~55 Ω (Typical) | | **Impedance @ 100 MHz** | ~135 Ω (Typical) | --- ### 4. Key Applications and Benefits The primary purpose of this component is to act as a "choke" to eliminate unwanted electromagnetic noise in electronic systems. * **Common Mode Choke:** When a cable is passed through the center of the ring, it creates an inductance that opposes common-mode noise currents without affecting the signal. * **Applications:** * Industrial power supplies and inverters. * Consumer electronics (AV equipment, appliances). * Communication lines to prevent data corruption. * Medical equipment requiring high electromagnetic compatibility (EMC). * **Ease of Use:** This is a solid core, meaning it must be slipped over the cable during the assembly process (unlike "split" cores which can be clipped on later). ### 5. Installation Note To increase the effectiveness of the suppression, engineers often wrap the cable through the core multiple times ($N$ turns). The impedance increases proportionally to the square of the number of turns ($N^2$). ```markdown Impedance Calculation: Z_total = Z_single_turn * (N_turns)^2 ```