What is a power frequency transformer

Power frequency generally refers to the frequency of commercial power, which is 50 Hz in China and 60 Hz in other countries. And can change the frequency of alternating voltage transformer, is called the power frequency transformer.

Power frequency transformer is known as low-frequency transformer, which is different from high-frequency transformer used in switching power supply. Power frequency transformer is widely used in traditional power supply in the past, and the stability mode of these power supplies adopts linear regulation, so those traditional power supplies are also called linear power supply.

The principle of power frequency transformer is very simple, and it is not complicated to deduce the relevant calculation formula in theory, so everyone has formed a view: it is too simple, there are only three or four calculation formulas, and there is nothing to study. When designing, as long as it is based on those simple formulas, it will succeed immediately.

In my opinion, the above understanding has both merits and merits. Merits: according to the calculation formula, you can quickly calculate the results and solve the problem. Merits: do you know the performance of the product you designed? Is the design reasonable? Has the design been optimized? How about the economy?

For example, it is a very complicated problem to select the iron core specification according to the power, because there are many factors involved

S = K·Sqrt(P) (1)

This is a practical method, but we should also realize that it is a simplified design method, and there is waste in most cases. This design method is not necessary for amateurs to discuss (only occasionally design a transformer for their own use), but it is worth discussing for enterprises. When this design method is adopted in large quantities in products, It reflects the reduction of economic benefits.