EI type insert core power transformer has the advantages of simple structure, low cost and wide application. Because the core sheet and its supporting coil skeleton, clip frame and other parts have been formed series and mass production, it is the most used type of core structure in civil electronic equipment.

The calculation method of EI chip core power transformer is basically the same as that of C-core power transformer. In the calculation of EI type insert core power transformer, the following points must be very careful.

(1) The materials used in EI type core pieces are very complicated

Cold-rolled non-oriented silicon steel strip (plate), cold-rolled oriented silicon steel strip (plate); Its variety is more, from high grade to low grade: its core processing technology is very different, there are annealed sheets (black sheets), non-annealed sheets (white sheets). Therefore, the electromagnetic properties of the core pieces of the same size vary greatly. In addition, even if the material and processing technology are the same, the electromagnetic properties of different sizes of core pieces are also very different. In order to select the iron core reasonably and determine the electromagnetic parameters of the iron core correctly, it is necessary to measure the magnetization curve and iron loss curve of various iron core pieces, and determine the magnetic induction intensity and the magnetic field strength and iron loss per kilogram under this magnetic induction intensity according to the measured curve. If the core sheet supplier can provide the relevant curve, the electromagnetic parameters of the core sheet can be selected according to the curve provided by the supplier.

(2) The requirements for the use of EI type insert core transformers vary greatly.Such as ambient temperature, allowable temperature rise, insulation and safety, installation structure, etc.

Ambient temperature The usual ambient temperature requirements are +25 ° C, +40 ° C, +55 ° C and +70 ° C.

Power Rating: EI transformers are well-suited for low to medium power applications (generally below 5 kVA). When choosing a transformer, consider the volt-ampere (VA) rating of your device and select a transformer with a slightly higher VA rating to handle potential surges.

Noise: Because of the open core construction, EI transformers can generate more audible noise compared to toroidal transformers. This might be a concern for noise-sensitive applications like audio equipment.

Temperature: EI transformers with lower efficiency will generate more heat, so factor in ventilation or select a transformer with a higher temperature rating for demanding environments.