What is the effect of the shape of the high-frequency transformer core on the operation of the transformer?
A high-frequency transformer is a device that converts an alternating voltage,a current,and an impedance.When an alternating current is passed through the primary coil,an alternating magnetic flux is generated in the iron core(or the magnetic core)to induce a voltage(or current)in the secondary coil..The transformer consists of a core(or core)and a coil.The coil has two or more windings.The winding connected to the power supply is called the primary coil,and the other winding is called the secondary coil.The core of the transformer includes a can core,an RM core,an E core,an EC,ETD and EER core,a PQ core,an EP core,an EP core,a toroidal core,etc.So,how do these cores affect the operation of the transformer?Please see the specific analysis below.
Can core
The skeleton and windings are almost completely wrapped by the core,which makes it very effective for EMI shielding;the core size of the can is in accordance with IEC standards,and the interchangeability is very good at the time of manufacture;the simple skeleton can be provided(no pin)And PCB board mounting skeleton(with pins);due to the shape of the can shape,it is more expensive than other types of cores of the same size;because its shape is not conducive to heat dissipation,it is not suitable for high power Transformer inductor.
RM core
Compared with the can type,the two symmetrical sides of the can type are cut off.This redesign is more conducive to heat dissipation and large-sized lead extraction.Compared with the can shape,it saves about 40%of the installation space;Needle type and pin type;can be installed with a pair of clips;RM type core can be made into a flat shape(suitable for the current planar transformer or directly assembling the core to the printed circuit board circuit with the windings already designed)Although the shielding effect is not as good as the can type,it is still good.
E type core
Compared with the can core,the cost of the E core is much lower,and the winding and assembly are relatively simple.This core shape is now the most widely used,but its disadvantage is that it cannot provide self-shielding;The E-core can be installed in different directions,or it can be applied with a larger amount of power;this core can be made into a flat shape(which is the popular core shape of planar transformers);it can also provide needle-free and plug-in Needle-type skeleton;because of its very good heat dissipation and can be used in combination,generally high-power inductors and transformers use magnetic cores of this shape.
EC,ETD and EER cores
These types of core structures are between the E and can type.Like the E-core,they provide enough space for large-section lead-outs(suitable for low-voltage currents in switching power supplies);these shapes also have very good core heat dissipation;they are cylindrical in the center column and are identical Compared with the rectangular parallelepiped,the length of the single-turn winding is shortened by 11%,which causes the copper loss to be reduced by 11%,and the core can provide a higher output power;while the central column is cylindrical and the cuboid center Compared with the column,the hidden danger of breaking the insulation of the winding wire due to the rectangular corners during winding is also avoided.
PQ core
The PQ core is specifically designed for inductors and transformers for switching power supplies.The PQ shape design optimizes the ratio between core volume,surface area and winding area;this design makes it possible to use the smallest core to provide maximum inductance and maximum winding area;this design In order to obtain the maximum output power under the minimum transformer volume and weight,and occupy the minimum PCB installation space;it can be mounted and fixed by using a clip;this effective design also makes the magnetic core cross-sectional area of??the core more Uniform,so this core structure also allows for fewer work hotspots than other core designs.
EP type magnetic core
The circular center column of the EP type core has a three-dimensional structure.In addition to the end that is in contact with the PCB board,the winding is completely wrapped and the shielding is very good;this unique shape minimizes contact during assembly of the two cores.The effect of the air gap formed by the face and provides a larger ratio of volume and total space utilization.
Toroidal core
For the manufacturer,the toroidal core is the most economical,and its cost is the lowest among the various cores that can be compared;the cost of additional and assembly is equal to zero due to the use of the skeleton;The wire machine is wound;its shielding is also very good.
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