| 摘要 |
<p>PURPOSE:To provide a failure detector for contact output type instrumentation unit in which the function of each output contact can be confirmed in operating state of the unit. CONSTITUTION:The failure detector comprises an auxiliary relay connected in series with each output contact of a contact output type instrumentation unit, a resistor circuit 4 connected in parallel with a power supply 3 for detector, a detection circuit 5, and a switch circuit 6. The resistor circuit 4 comprises a plurality of resistors Rn connected in series, the detection circuit 5 comprises a comparator 7 delivering a signal when the input voltage is abnormal, and the switch circuit 6 comprises b-contacts LLX, LX, HX and HHX each forming a bypass circuit for each resistor Rn of the resistor circuit 4.</p> |
