## B66337 Series (ETD 44/22/15) Ferrite Cores The **B66337** series refers to a specific size of **ETD (Economic Transformer Design)** ferrite cores manufactured by **TDK Electronics (formerly EPCOS)**. These are essential passive components used in the construction of high-frequency transformers and inductors. --- ### 1. Key Technical Specifications The B66337 follows the **ETD 44/22/15** standard dimensions. The nomenclature represents the Physical size of the core (approx. 44mm width, 22mm height, 15mm depth). | Parameter | Value (Approx.) | | :--- | :--- | | **Core Shape** | ETD (Economic Transformer Design) | | **Magnetic Path Length ($l_e$)** | 103 mm | | **Effective Area ($A_e$)** | 173 mm² | | **Minimum Area ($A_{min}$)** | 172 mm² | | **Effective Volume ($V_e$)** | 17800 mm³ | --- ### 2. Common Material Grades The B66337 core is available in different ferrite materials depending on the application requirements (frequency and power loss). * **N27:** Best for power transformers in the frequency range up to 100 kHz. * **N87:** A high-frequency power material for SMPS (Switch Mode Power Supplies) up to 300 kHz. * **N97:** Offers lower power losses and higher saturation flux density than N87. * **N95:** Optimized for low power losses over a wide temperature range (25°C to 100°C). --- ### 3. Components of a Complete Assembly To build a functional electronic part using the B66337, you generally need three items: 1. **Core Halves:** Two pieces of B66337 (usually gapped or ungapped). 2. **Coil Former (Bobbin):** The plastic frame where the wire is wound (e.g., B66338 series). 3. **Yoke (Clamps):** Stainless steel clips to hold the two core halves tightly together to minimize the air gap. --- ### 4. Applications These parts are typically found in high-power electronic circuits: * **Switched-Mode Power Supplies (SMPS):** Main power transformers for AC/DC converters. * **Inverters:** Used in solar power systems and UPS (Uninterruptible Power Supplies). * **DC/DC Converters:** High-efficiency voltage stepping in automotive or industrial gear. * **Inductors:** Power factor correction (PFC) chokes. --- ### 5. Part Number Example A typical part number looks like this: `B66337G0000X187` * **B66337:** The size/series (ETD 44). * **G / Gxxx:** The air gap size (0 = ungapped). * **X187:** The material grade (in this case, N87). ---