Reasons why the miniature current transformer cannot be used as a voltage transformer

- Aug 28, 2020-

In general, miniature current transformers are generally composed of relatively small primary and secondary currents, usually mA level, and the study found that the currents on both sides are not equal. The study speculates that it may be due to a certain isolation between the two sides. It should also be explained here that when it is actually used, it is generally connected to a sampling resistor of about several hundred ohms for the second time, and it is not recommended to open the output. Another point is that even if the miniature current transformer is open, the generated voltage will not be very high, which will not harm the safety of the human body.

Having said so much, we understand that the miniature current transformer cannot be opened for the second time, for the sake of not mentioning it for the time being, we mainly talk about its consequences.

In fact, it can be said that because the iron core of our miniature current transformer is non-linear, when the secondary open circuit is performed, the excitation current in it is increased. However, the excitation current will not increase all the time. If it is large enough, the core will be saturated and the magnetic flux will be limited. In layman's terms: after a second open circuit, there is not necessarily a large magnetic flux and a high voltage.

Regarding this point in the miniature current transformers, we can say this: in actual life, we usually work because the protection type transformers work normally and the low pass is low. In other words, it is the same as the margin and the measurement type. saturation. Therefore, the same is a secondary open circuit, the secondary current generated by the miniature current transformer will be higher than the general protection transformer!