1/14/2024 0 Comments Magnetic flux calculator coilIt must be said that if the specified flux density is exceeded (if the core is saturated) the toroid overheats and its permeability changes Iron powder cores do not get damaged and return to their initial characteristics, while ferrite cores can be permanently damaged.Īs regards the construction of the coils, the power of the signal in transit must be considered with modest signals, enamelled copper with a section of 0.18 to 1 mm is fine if the power is high, it is necessary to use rigid wire covered in PVC (like that used in electrical systems) with a large diameter, even 1.5 or 2 mm (the advice of “some” is to wrap the core with insulating tape before building I have never shared the coil itself… especially if you work on VHF). The ferrite core (FT series) has a greater permeability so fewer turns are needed for the same inductance (ideal for RF chokes and broadband transformers) however it is less stable as the temperature varies. The iron powder toroid (T series) is able to tolerate high powers (the T300 for example supports 800 Watt RF) and is subject to minor variations in permeability therefore excellent for oscillators, an example is the yellow core 6 which is very stable as long as the coils are glued to the core to avoid vibrations and movements of the wire with consequent frequency drifts. Generally the higher the permeability, the lower the recommended working frequency. As H increases, B tends to saturate as there is a limit induction value when all the magnetic dipoles of the material align with the imposed field. Permeability is the ratio between flux density in the material (B) and flux density in air (H): in simple terms it is the measure of the relative ease with which a magnetic flux is established, the symbol that represents it is the Greek letter µ ( µi = micro index ). The salient characteristics of these nuclei are: the dimensions, the permeability (µ), the frequency range and the maximum applicable power. There are many magnetic materials used for the construction of toroidal cores but the two main ones are: iron powder and ferrite. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |