The current transformer tester is in the route of supplying and using electricity, the size of the current varies greatly, ranging from a few amperes to tens of thousands of amperes. In order to facilitate the accurate measurement of instruments and dashboards, they must be converted to a more uniform current. In addition, the working voltages on the supply circuit lines are relatively high. For example, immediate accurate measurement is very risky for all instruments, dashboards and people. of. Therefore, the current transformer tester of the design scheme has the function of current transformer and electrical equipment isolation.

The majority of analog current quantity digital display instruments are ampere-level, so most of the secondary current of the current transformer tester is ampere-level (such as 5A, etc.), and the data signal sampled by the electronic computer is generally mah level ( 0-9V, 4-50mA, etc.). Therefore, a small current transformer tester (with the secondary current level of mah) is selected as the highway bridge between the current transformer tester and the electronic computer sampling data signal to carry out the secondary conversion of the current.

The current transformer tester is composed of a primary electromagnetic coil, a secondary electromagnetic coil, an iron core, an insulating layer support point, and a group outlet terminal. The iron core of the current transformer tester is made of laminated ferrite cores. Its primary electromagnetic coil is connected in series with the main power circuit, and according to the measured current I1, it causes alternating magnetic flux in the iron core to make the two The secondary electromagnetic coil magnetically induces a relative secondary current I2 (its rated voltage is 5A). If the loss of the excitation regulator is ignored, I1n1=I2n2, where n1 and n2 are the coil turns of the primary and secondary electromagnetic coils. The converter ratio of the current transformer tester is K=I1/I2=n2/n1. Because the primary electromagnetic coil of the current transformer tester is connected to the main power circuit, the primary electromagnetic coil must be grounded with an insulating material consistent with the working voltage of the primary route to ensure the safety of the secondary circuit and personal safety. The secondary circuit is composed of the secondary electromagnetic coil of the current transformer tester, the instrument panel and the current electromagnetic coil of the automobile relay in series. Current transformer testers can be roughly divided into two categories, current transformer testers for accurate measurement and current transformer testers for maintenance.