Definition of High Frequency Transformers

In fact, the definition of a high-frequency electronic transformer is clear. In order to show the true nature of high-frequency electronic transformers, it is necessary to clarify the concept of the transformer, electronic transformer, and high-frequency electronic transformers to eliminate misunderstanding.

First, we need to figure out what is a transformer. Transformer is based on the principle of electromagnetic induction work, which refers to the primary winding of the coil on the AC voltage, induction of output voltage in the secondary winding, thereby transferring energy, transforming voltage (or signal), and electrical isolation.

To produce electromagnetic induction, an AC voltage must be applied to the primary winding. The kind that uses DC voltage as its operating power source is the inverter that converts DC power into AC power.

As long as there is electromagnetic induction, the transformer can work. A magnetic core is not required. For example, an electronic transformer with an operating frequency of MHz is a hollow transformer made from a printed circuit board. The term "high-frequency electronic transformer" is "magnetic transformer used in inverter circuits", which is a double misunderstanding, including inverter circuits in the scope of transformers, but also that transformers must have a magnetic core.

Transformers transmit energy by electromagnetic induction, independent of the operating frequency. The amount of energy transferred is related to the material, structure, size and operating frequency of the transformer. If the transmitted energy is a fixed value, the operating frequency is high, the number of times the energy is transmitted in a certain period of time, and the energy transmitted each time can be small, the transformer uses less material and has a small structure. It is a misconception that transformers transmit limited energy and use high frequency to increase the transmission energy. The use of pulse width modulation (PWM) to vary the power and voltage of the transformer is just an additional control method. Not only can high-frequency transformers be used, but also low-frequency transformers can be used. 

There is a difference in the way high-frequency and low-frequency transformers transfer energy after PWM control, and it is also a misconception that high-frequency and low-frequency transformers change voltage in different ways.

Next, we need to figure out what is an electronic transformer. An electronic transformer is a transformer used in electronic circuits and electronic devices. If the scope is expanded, it includes all electromagnetic components such as transformers, inductors, and transformers used in electronic circuits and electronic equipment. Electronics are not limited to power electronics, but also include industrial electronics, information electronics, wireless electronics,  and microelectronics. Although electronic transformers are different from power transformers, they are not different from RF signal transformers, nor are they limited to "power in switching power converter circuits". transformer". Power transformers are just one type of electronic transformer. Therefore, the electronic products are limited to power electronics, and the electronic transformer products are limited to power transformers is a misunderstanding.

Then, we have to figure out what is a high-frequency electronic transformer. Now the electronic transformer working frequency of high, medium and low division has a common saying, that is, the working frequency at 50Hz or 60Hz is called industrial frequency, or lower frequency is called low frequency; 60Hz to 20kHz is called medium frequency, 400Hz for medium frequency, not industrial frequency; 20kHz or more is called high frequency. Why choose 20kHz as the limit? Because 20kHz is the upper limit of audio, more than it can not hear the audible noise. Therefore, the operating frequency is more than 20kHz, from 20kHz to MHz level, GHz level for high frequency.

High frequency can also be divided into high frequency (20kHz ~ 50kHz), medium and high frequency (50kHz ~ 200kHz), high frequency (200kHz ~ 1MHz), ultra-high frequency (more than 1MHz), but all are high frequency, not because the application of different power, the understanding of high frequency is different. It is a misconception that the range of high frequency is different under different power.