6 flat transformer number meaning

Two types of flat transformer numbers and their contents are shown in Figure 6 (a) (FTI) and (b) (CTI). Description as follows:

(1) in the CTI series, if the center tap is required, a "C" word is selected for the optional turn ratio. For example 3C=3 + 3 indicates a turn ratio of the center tap for 3:1.

(2) in the CTI series, the primary and secondary winding transformer and inductor are made according to the standard in the module. And FTI series, the original side winding of the transformer is not installed. When in use, the user can turn around the system according to the required turn ratio. Because the primary winding is standard and the number of turns is very small, so the method of winding the primary winding is very simple. The primary winding must pass through all the modules, and with enough turns to obtain the required turn ratio.

7 conclusion

Through the calculation and analysis, it can be concluded that the characteristics of high frequency flat plate transformer:

(1) current distribution

The typical side winding of the flat plate transformer is provided with a plurality of parallel coils. Each side winding is coupled to the same primary winding. So, have equal ampere ampere turns and primary winding secondary winding current generated by the (ignoring the excitation current). This characteristic is especially useful for parallel rectifier circuits. The current distribution of the windings is equal, and no current resistance and other elements are needed in the parallel rectification circuit.

(2) a very high current density

Plate transformer has excellent temperature rise characteristic design. Because of these characteristics, it can achieve a very high current density in a very small package.

(3) high efficiency

Adjust leakage inductance, so that it can have a very fast switching time, very low cross loss, can make it achieve high efficiency. This transformer secondary side winding and the original side winding between turns conduction loss is very small.

(4) high power density

Because the size of the flat plate transformer is very small, it has excellent temperature dissipation characteristics, so it can be closely related to the semiconductor devices and inductors packaged together to achieve high power density. Its current density can be done 30A/ module.

Figure four 5 core modules Xx4A - 1B/2B/3B - FTI/CTI (turn ratio 8:1)

Fig. two 6 types of flat transformer and its contents

(5) low cost

The whole transformer is composed of a small amount of cheap components, coupled with the assembly is very convenient, so the cost of the transformer is very low.

(6) saving the cost of the components it connects to

Because of its low leakage current, the switching loss is very low, and the stress on the connecting component is reduced. Therefore, the parts which are connected with the components can be used for low power rating parts with lower cost.

(7) excellent heat dissipation characteristics

Planar transformer is a small component with high surface area volume ratio and short heat channel. Is conducive to heat. The turns between the primary and secondary windings are very small. The unique geometric shape of the magnetic core can effectively reduce the magnetic core loss. So it can achieve high magnetic flux density. It can work in between: 130 DEG C - 40.

(8) low leakage inductance

The good coupling between the winding and the winding can keep the leakage current in the winding turns to be kept at a minimum. The connection between the output end to the auxiliary part is short and tight fitting, so the leakage inductance of the winding is the smallest.

(9) excellent high frequency characteristics

Before this, when the transformer is operating at high frequency, the switching loss will increase and the transformer will overheat. The emergence of flat-panel transformers, so that these problems can be solved. The flat transformer can be designed as a high frequency transformer, which provides an economical and good transformer module. It can work between 100kHz ~ 500kHz.

(10) simple structure

The flat transformer is composed of a small number of components and a minimum of windings, which are especially suitable for automatic assembly.

(11) low profile

The magnetic core used in the flat transformer is very small, and can be arranged on the surface of the flat plate. Each core element is in the range of 8mm ~ 25mm.

(12) high insulation strength

It is easy for the plate transformer to be insulated according to the required number of layers and thickness. Can be according to customer's request for leakage distance dielectric insulation. The voltage between the primary and secondary windings is greater than 40000V.