A magnetic, high flux U satisfied degree is low, the core in the low frequency to withstand the big electric current, the greater the impedance change with current and capacitive reactance.
Core winding magnetic core fever also tell core loss is too big, the power is converted into heat energy, rather than into magnetic energy, the energy consume, nickel material core bandwidth, usually have a balanced relationship between Q and U, U value the higher the Q value, the lower the vice is also.
U value lf work difficult, but loss is small, the U value of high frequency work more easily, but the core loss is too big, power loss is big, basically difficult to work continuously.
Using the U value of 400 core winding should be able to greatly reduce the loss of magnetic.
Although low inductance, but can increase the number of coil to solve.
In 1:4 transformer for example, 1 primary into two times;
2 secondary to 4 times, to double the total length of this winding, high transmission frequency will reduce accordingly.
Second, the Curie temperature some cheap core winding Curie temperature 165 ℃, the temperature reached after immediately lose magnetism, as air medium;
Permanent change occurred after recovery at room temperature, magnetic, magnetic permeability was reduced by 10%, the circular on the output transformer of power amplifier applications of magnetic materials if working temperature exceeds the Curie temperature, a moment can be burned between the output power tube, imports -
Curie temperature data of 43 material don't know, domestic NXO -
100 is 260 ℃, R -
400 is 350 ℃, the output power began to decline the point as the circular and temperature limit, from the experimental results of the past, 55 degrees, the EMI circular and has not been a drop in output power.
Be difficult, but the loss is small, U value of high frequency work more easily, but the core loss is too big, power loss is big, basically difficult to work continuously.
Three, each of the core material determines its working frequency of working frequency, so you need to choose according to the specific frequency magnetic core material.
Such as NXO -
100 material, magnetic flux is 100, the operating frequency of 15 MHZ.
80 materials of magnetic ring, magnetic flux is 80, the working frequency of 30 MHZ.
Circular and low working frequency of circular and forced to work under high frequency, there will be a great loss and fever, when the circular fever more than Curie temperature, electric performance is mutated, also can't work normally, total, should choose to magnetic ring, not the shape or size can, need to understand its actual parameters, otherwise if problems arise, such as standing wave, high frequency width is too narrow, circular and severe heat or burn out, etc. , all don't know the reason comes from where