What are the differences between high frequency transformer and low frequency transformer

Generally, low frequency transformer refers to "power frequency transformer", which works at (50 Hz) to change the voltage. The iron core of low frequency transformer is usually silicon steel sheet with high permeability.

High frequency transformer refers to the transformer that works in high frequency and plays the role of energy exchange. Because the frequency of magnetic field is very high, there will be eddy current in silicon steel sheet (the conversion speed of small magnet in silicon steel sheet can't keep up), so high frequency transformer generally uses "high frequency ferrite" as the magnetic core.

Low frequency transformer is a low-voltage transformer whose windings are in the same primary and secondary windings. The primary and secondary windings are directly connected in series, and the low-voltage transformer. According to the structure, it can be divided into adjustable pressure type and fixed type. The coupling of auto coupling means electromagnetic coupling. Ordinary low-voltage transformer transfers energy through electromagnetic coupling of primary and secondary coils. There is no direct electrical connection between primary and secondary coils. The primary and secondary coils of low-voltage transformer have direct electrical connection. Its low-voltage coil is a part of high-voltage coil. Low voltage transformers and other protective devices are also used for communication optical cables. Here, two or more coils are wound on a closed iron core.

The difference between high frequency transformer and low frequency transformer lies in the difference of working frequency, which leads to some differences in material selection. The working principle of low-frequency transformer is the same as that of high-frequency transformer. No matter the working frequency is high or low, the energy is transmitted through electromagnetic induction.

Low frequency transformer when the coil into the AC, AC current according to the coil. The transformer core causes AC electrostatic field, the main AC current flow causes self induced potential difference on the first coil, and the other coil (i.e. the second coil) causes AC inductance. By changing the relationship between the turns ratio of primary and secondary coils to change the voltage of primary and secondary coils, the voltage conversion is realized. Generally, the turns ratio is 1.5:1 ~ 2:1. It is also because the main circuit and the secondary circuit are connected immediately, which leads to the risk of exceeding the circuit leakage. Severe crackdown, so it can not be used as walking lamp transformer.

Because the frequency of high frequency is different from that of low frequency, high frequency can only be used in the circuit with high frequency and the excitation source frequency matches the transformer frequency, while low frequency can not be mixed, even if the frequency of high frequency does not match.

If the transformer transmits a certain amount of energy with high working frequency, more times of energy transmission within a certain period of time and less energy per transmission, the transformer will use less materials and small structure size. Therefore, the general high-frequency transformer has less coil turns and can be very small in size, while the low-frequency transformer has more coil turns.

Characteristics of low frequency transformer

Because the calculated capacity of low voltage transformer is less than the rated capacity. Therefore, under the same rated capacity, the main size of low-voltage transformer is smaller, and the effective materials (silicon steel sheet and conductor) and structural materials (steel) are correspondingly reduced, thus reducing the cost. Along with the reduction of effective materials, the consumption of copper and iron is also reduced, so the working efficiency of low-voltage transformer is very high. In addition, due to the reduction of key specifications and quality, a single shipping standard can produce a larger volume of low-voltage transformer under the allowable shipping standard. But in low voltage transformer, the above advantages are obvious only when k ≤ 2.