短語(yǔ)詞組短語(yǔ)track -circuit signalling 軌道電路信號(hào)track rate of track -hold circuit 跟蹤hold drift of track -hold circuit 跟蹤;保持器保持漂移電路Double -track circuit 雙線軌道電路圖distributed track -and-hold circuit 分布式采樣保持電路track circuit frequency -shift signal 軌道移頻信號(hào)center -fed track circuit 中央饋電式軌道電路Value -type track circuit 閥式軌道電路 返回 track circuit