secondary loop

例句：

1. 1.The engineer designed the new machine with a secondary loop to improve efficiency.
   工程师设计了这台新机器，带有一个次级回路以提高效率。
2. 2. In the electrical system, the secondary loop is responsible for carrying electricity from one part of the grid to another.
   在电力系统中，次级回路负责将电能从一个电网部分传输到另一个部分。
3. 3. The secondary loop was used to connect two different circuits together without affecting the main power line.
   次级回路被用来连接两个不同的电路，而不会影响到主电源线。