| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve the problem of a door closing security device constituted only by a circuit for detecting a frequency of sine wave output from a speed meter generation unit in which a door is not opened due to a failure of the detecting circuit in spite of a railroad vehicle being stopped by driving a door opening interlock relay of the railroad vehicle. <P>SOLUTION: The door closing security device configured to detect a speed of the railroad vehicle includes a fail-safe provided in a circuit for detecting the speed. Namely, the door opening interlock relay 8 is driven by superposition of a circuit 4 for detecting frequency and the circuit 5 for detecting voltage. <P>COPYRIGHT: (C)2013,JPO&INPIT |
