湖北赤马山铜矿竖井的提升过卷讯号,过去一直采用笨重的行程开关。由于井内潮湿,节点锈蚀,常造成迥路不通,机械部分卡死,不能带动节点断开,过卷讯号极不可靠,影响乘罐人员和设备安全。该矿坑口电工组经过多次试验,制成了一台半导体无触点过卷讯号装置,于一九七二年一月正式用 Hubei Red Hill copper shaft hoist signal over the past, has been using the bulky travel switch. Due to the well in the well, the node is corroded, often resulting in a barrier, the mechanical part of the stuck, can not drive the node off, over-roll signal is extremely unreliable, affecting tank crew and equipment safety. After several experiments, the mine pit mouth electrician group made a semiconductor non-contact over-roll signal device, formally used in January 1972