HF (Hi-Flux)
50/50 Nickel, Iron alloy powder material. No thermal ageing.
HF (Hi-Flux) cores are designed to operate up to about 6500 gauss, as opposed to the 3500 gauss limit of standard MP (Mollypermalloy) cores. There is some sacrifice in stability because less distributed air gap is required to obtain the reduced permeabilities. Core losses are also higher than MP, although because of their high flux and power-handling capabilities, HF cores are used as energy storage inductors and in line output (flyback) transformers in SMPS. They are also especially well suited for DC and line frequency noise filter inductors (such as the differential-mode choke in a switched mode power supply). Their high saturation flux density can be used to advantage because core loss is negligible at the low frequencies of these applications. Available in permeabilities from 14µ to 160µ.
- Temperature stable
- High energy storage per unit volume
- Available graded into small increments of permeability range
- Higher Bmax than MPP cores
- Permeabilities available up to 160 compared to 100 for Iron Powder
- Higher core losses than MPP
- Manufacturing costs are relatively high, making Hi-Flux cores second only to
- MPP cores in cost terms
- The available shape is limited to toroidal only, due to very high pressing pressures required.
- Energy storage inductors used in switch-mode power supplies
- DC and line frequency noise filter inductors
- Power factor correction (PFC) circuits
- Unidirectional drive applications such as line output (flyback) transformers and pulse transformers.
