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What a high-frequency transformer is and how a high-frequency transformer works.
Jan 24, 2017

High-frequency transformer manufacturers first explain to you what a high-frequency transformer is and how a high-frequency transformer works.


1. The excitation current is generated by the voltage applied to both ends of the coil. After the current is generated, a reverse electromotive force is generated, which has the tendency to hinder the change of the external voltage. However, this voltage is not stable and changes with the external voltage. Variety. Of course, this external voltage is relatively smooth, such as parabolic voltage. If it is suddenly disconnected at a certain level, it will produce a very high reverse pulse, which will be higher than the original level.


2, the role of excitation current? That is to maintain the primary coil of magnetic flux changes, that high-frequency transformer manufacturers can not understand this, in fact, the role of excitation current is to offset the loss of the transformer and some can not be transferred to the transformer secondary energy? Your understanding of the excitation current is basically correct, because the transformer is not able to achieve the ideal state after all.

Although the secondary is unloaded, a certain amount of power input is still required to maintain the voltage. Moreover, because of iron eddy currents and other reasons, this input will increase with the increase of secondary load. 


3. The no-load current of the transformer includes excitation current and iron current. The excitation current is also referred to as excitation current or magnetization current. Because the iron consumption current is very small, the no-load current is mainly used for excitation, so sometimes the idle current is also called excitation current. The following mathematical expressions can be used: Magnetizing current = magnetizing current = magnetizing current No-load current = magnetizing current + iron current The transformer's no-load current is usually only a few percent of the rated current of the transformer. So no special protective measures are needed. However, the transformer no-load closing inrush current is more than 5 times of the rated current of the transformer, and it is necessary to set differential protection so as to avoid malfunction of the high voltage protection.


High-frequency transformers are power transformers whose operating frequency exceeds mid-frequency (10kHz) and are mainly used as high-frequency switching power transformers in high-frequency switching power supplies. High-frequency transformer manufacturers also feel that they are also used in high-frequency inverter power supplies and high-frequency inverter welding machines. For high frequency inverter power transformer. According to its operating frequency, we divide the high frequency transformer into the following categories:


3. The no-load current of the transformer includes excitation current and iron current. The excitation current is also referred to as excitation current or magnetization current. Because the iron consumption current is very small, the no-load current is mainly used for excitation, so sometimes the idle current is also called excitation current. The following mathematical expressions can be used: Magnetizing current = magnetizing current = magnetizing current No-load current = magnetizing current + iron current The transformer's no-load current is usually only a few percent of the rated current of the transformer. So no special protective measures are needed. However, the transformer no-load closing inrush current is more than 5 times the rated current of the transformer, and differential protection is needed to prevent malfunction of the high-voltage protection.


1. kHz class high frequency transformer, it refers to the high frequency transformer whose working frequency is from 20kHz to several hundred kHz;

2.MHz high-frequency transformer, which refers to a high-frequency transformer whose operating frequency is above 1MHz.


According to the working frequency band, high-frequency transformer manufacturers will be divided into:

1. Single-frequency or narrow-band high-frequency transformers, which means that the operating frequency is a single frequency or a very narrow frequency band, such as transformer transformers, oscillator transformers, etc.;

2. Broadband transformers, which refer to transformers that operate over a wide frequency range, such as impedance transformers, communication transformers, and broadband power amplifier transformers.

High-frequency transformer manufacturers believe that high-frequency transformer transmission power is relatively large, the power devices generally use IGBT, due to IGBT shutdown current tailing phenomenon, so the operating frequency is relatively low; transmission power is relatively small a, you can use MOSFET, work The frequency is relatively high


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