| 摘要 |
PURPOSE:To detect the frequent generation of instantaneous faults also as a fixed fault by counting up a fault continuing time and fault generation frequency. CONSTITUTION:The shown diagrams are time charts obtained when a short clock interrupting fault shorter than time TC is generated 3 times during a period time T1 and regarded as a fixed fault. In the time chart, (a) shows the output signal of a fault detecting circuit 10, (b) shows the output signal of a period pulse generating circuit 40, (c) shows the counting value of a fault generation frequency counting circuit 30, (d) shows the output signal of the circuit 30, (e) shows the output signal of a fault continuing time counting circuit 20, (f) shows the output signal of an OR gate 50. The fault continuing time and the fault generation frequency are counted up and the fault continuing time value decided as a fixed fault, the fault generation frequency value, or a period pulse generation interval value can be optionally set up. Thus, the frequent generation of instantaneous faults also is detected as a fixed fault. |
