If you find your design is asking you for 'good' value for saturation field to get your volts per turn up, then try doubling the design frequency, and instantly you get twice the power throughput. The reason your datasheets give you field at a given H is that to get that field, you need to supply that H, and the winding dissipation rises as H^2 (as I^2), so there a large penalty in pushing further round the BH curve. Generally, low loss ferrites have rather soft BH curves, with no 'knee' to put a single number on. In ferrites, now that we have nice fast switching devices, it's generally dissipation that limits you first, so saturation is rather less important than it would be with, for instance, an iron core operated at mains frequency. There are two main things that set the maximum field for the magnetic core of an inductor, and we have to respect both of themĪ) saturation - leading to reduced inductanceī) power dissipation in the material - leading to excess core temperature So, my question is: in cases like this, in which no explicit "field near saturation" parameter is given, what maximum value of the magnetic field should I use in order to calculate the maximum current in the inductor? Do I just rule of thumb 200mT, or is there some way of inferring something from other specs? Here's another table with several values for "Flux Density Field Strength", and although the maximum flux density seems about right, the field strength values are all suspiciously round. Saturation)", which is about 300mT (what I expected). For example, this material datasheet gives me "Flux density (near
However, I am having trouble finding out when the cores will saturate from manufacturer's data. I want to wind my own ferrite core inductors for some power conversion.
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