| 摘要 |
<p>PURPOSE:To reduce the used number of current transformers and current-voltage converting circuits to detect the abnormality of control elements by measuring the action time of a doubled making control element and that of a doubled breaking control element respectively on the basis of the current of one current transformer. CONSTITUTION:When a current flows to making solenoids 1A, 1B, a plunger is operated to drive mechanism for closing switching equipment 2. Pallet switch contacts 3A, 3B are opened being interlocked with the closing action of the equipment 2. The current flowing in both making control elements 8A, 8B is detected by one current transformer 12, and the detected current is converted by a current-voltage converting circuit 13. The output voltage of the circuit 13 is applied to a first comparing circuit 17 and a second comparing circuit 18. The output of the comparing circuits 17, 18 is inputted into an action time measuring circuit 21, and the output of the comparing circuit 18 is inputted also into a control element state detecting circuit 26. When the output of the circuit 18 is inputted into the circuit 26, this state is stored by an output holding circuit 27, and a display part 28 displays this output.</p> |
