| 摘要 |
PROBLEM TO BE SOLVED: To improve precision of accident detection and prevent malfunction to the utmost while ensuring high speed property of breaking operation in the case of actual accident. SOLUTION: A numerical value conversion circuit 26 for accident judgment inputs a first and second quantities of state, and converts them to numerical values suitable for judging whether an accident occurred. A first to N-th accident judging circuits J1 to JN input the converted numerical values, and judge individually whether an accident occurred. A control signal output circuit 27 outputs a breaking command 20 to a semiconductor switch when an accident occurrence judging signal is inputted from a judging circuit. The judging circuit J1 has the lowest voltage judging level and the shortest judging time. The judging circuit JN has the highest voltage judging level and the longest judging time. |
