CONTROL METHOD AND DEVICE OF OBSTRUCTION WARNING INDICATING DEVICE ON RAILROAD-CROSSING LINE

摘要

PURPOSE:To monitor constantly the failure of the circuit and the breaking of cable between a controller and a light emitting device by constructing such as to circulate the entire circuit with or without obstruction on the railroad-crossing line though in the different current flow directions. CONSTITUTION:When there is no obstruction on the railroad-crossing line, an accident warning audible indication control relay is operated, and in the closed state of its operating contact point ER, a reaction relay EPR is kept operating with its operating contact point EPR' closed to the operating side so that the entire circuit is circulated. However, in such current direction, respective indicating lamps L1-L5 are not circulated but photo couplers PC6-PC10 and light emitting diodes P1-P5 are lighted respectively, and for instance, if a cable 9 is disconnected, the light emitting diode P1 is extinguished. If an obstruction is created on the railroad-crossing line and the operating contact point ER of the accident warning audible indication control relay is released, the reaction relay EPR drops and its contact point EPR' is closed to the dropping side. As a result, the current flow direction is reversed, and the respective indicating lights L1-L5 are extinguished in succession so as to emit the accident warning signals.