| 摘要 |
PURPOSE:To determine the length of a train correctly, by using a method by which a detector B is checked when the head of the train reaches a point where a detector A is provided and a method by which the detector A is checked immediately after the end of the train passes the point where the detector B is provided in a combination manner. CONSTITUTION:When a train T1 having a short composition is passing a rolling stock detector B, a light beam lb is shielded, a rolling stock detecting relay BLR is restored, and a reaction relay BLPR is operated. When the end of the train T1 has passed the detector B, the relay BLR is operated and the relay BLPR is restored. Since the operating state is maintained for a specified time period by damping characteristic, a relay LLc is operated, and the fact that the train T1 is short train is detected. Even though a short composition train T2 that follows the T1 is passing the detector B before the train T1 reaches the detector A, the short train length detecting relay LLc maintains the detection of the short composition train without the effect of the following train through a self-keeping circuit from a restoring contact point ALPR to the operating contact point LLc. |
