Switching power supply, electrical isolation method and ammeter

Abstract

The invention relates to a switching power supply, an electrical isolation method and an ammeter. The switching power supply comprises a first transformer and a second transformer, wherein an external power supply is coupled to a primary coil of the first transformer, a secondary coil of the first transformer is coupled to a primary coil of the second transformer, a secondary coil of the second transformer is coupled to a load, the first transformer is used for adjusting an input voltage of the external power supply to a first voltage signal by an electromagnetic effect of the primary coil and the secondary coil of the first transformer and inputting the first voltage signal to the primary coil of the second transformer so that the external power supply is electrically isolated with the second transformer, and the second transformer is used for adjusting the first voltage signal to a second voltage signal by an electromagnetic effect of the primary coil and the secondary coil of the second transformer and outputting the second voltage signal to the load so that the first transformer is electrically isolated with the load. By series connection of the first transformer and the second transformer, the electrical isolation of 10KV between the external power supply and the load is achieved.

Description

technical field [0001] The invention relates to the field of electrical technology, in particular to a switching power supply, an electrical isolation method, and an electric meter. Background technique [0002] With the development and improvement of science and technology, electric meters have become intelligent. Smart meters still require personnel to perform certain operations and maintenance. Among them, using the RS-485 interface of the meter to read its data is a basic function. In the smart electric meter in the prior art, the RS-485 interface and the power grid can withstand the 6KV pulse voltage isolation required by the national power grid at most. However, with the development of society and the surge of electricity consumption, the power system has higher and higher requirements for the safety and reliability of smart meters. Therefore, the 6KV pulse voltage isolation that can be tolerated in the prior art has gradually failed to meet the requirements of safet...

AI Technical Summary

Problems solved by technology

Increasing the size of the transformer makes the smart meter too large and inconvenient to use; and increasing the insulating material makes the production cost of the smart meter too high

Images