鼠标单击开关切换开合状态
通电后, 线圈产生磁力从而将铁片开关(衔铁臂)吸引下来
https://cc.xiaogd.net/?startCircuitLink=https://book.xiaogd.net/cyjsjdmw-examples/assets/circuit/cyjsjdmw-ch04-01-morse-telegraph.txt
原图
https://cc.xiaogd.net/?startCircuitLink=https://book.xiaogd.net/cyjsjdmw-examples/assets/circuit/cyjsjdmw-ch04-02-relay.txt