EFD Cores (8978252521*)
78 EFD CORE SET
78 Material
Inductive Components
Closed Magnetic Circuit
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Part Number: 8978252521
78 EFD CORE SET
EFD (Economical Flat Design) cores have been designed to maximize volume in a low profile geometry. EFD cores allow maximum throughput power density with reasonably low mass for board level installation.
EFD cores can be supplied with the center post gapped to a mechanical dimension or an ALvalue.
Weight indicated is per pair or set.
Weight: 16 (g)
| Dim | mm | mm tol | nominal inch | inch misc. |
| A | 25 | ± 0.50 | 0.984 | _ |
| B | 12.5 | ± 0.25 | 0.492 | _ |
| C | 9.1 | ± 0.30 | 0.358 | _ |
| D | 9.3 | ± 0.25 | 0.366 | _ |
| E | 18.7 | ± 0.60 | 0.736 | _ |
| F | 11.4 | ± 0.20 | 0.449 | _ |
| K | 5.2 | ± 0.20 | 0.205 | _ |
Chart Legend
Σl/A : Core Constant, le : Effective Path Length, Ae : Effective Cross-Sectional Area, Ve : Effective Core Volume
AL : Inductance Factor 
Explanation of Part Numbers: Digits 1 & 2 = product class and 3 & 4 = material grade.
| Electrical Properties | |
| AL(nH) | 2200 ±25% |
| Ae(cm2) | 0.58 |
| Σl/A(cm-1) | 10.4 |
| le(cm) | 5.88 |
| Ve(cm3) | 3.32 |
| Amin(cm2) | 0.55 |
AL value is measured at 1 kHz, B < 10 gauss.
A MnZn ferrite specifically designed for power applications for frequencies up to 200 kHz and low loss inductive applications to 500 kHz.
Available in 78 material:
RFID Rods
Toroids
Mated Parts
78 Material Characteristics
| Property | Unit | Symbol | Value |
| Initial Permeability @ B < 10 gauss | µi | 2300 | |
| Flux Density @ Field Strength | Gauss Oersted |
B H |
4800 5 |
| Residual Flux Density | Gauss | Br | 1500 |
| Coercive Force | Oersted | Hc | 0.20 |
| Loss Factor @ Frequency | 10 -6 MHz |
Tan δ/ µi | 3 0.1 |
| Temperature Coefficient of Initial Permeability (20 -70°C) | %/°C | 1.0 | |
| Curie Temperature | °C | Tc | >200 |
| Resistivity | ohm-cm | ρ | 200 |
**** Characteristic curves are measured on standard Toroids (18/10/6 mm) at 25°C and 10 kHz unless otherwise indicated. Impedance characteristics are measured on standard shield beads (3.5/1.3/6.0 mm) unless otherwise indicated.
Material Safety Data Sheet (MSDS)
Click here to download Complex Permeability vs. Frequency (CSV)
Ferrite Material Constants
Storage and Operating Temperature
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