| 摘要 |
<p>PURPOSE: To monitor the operation of non-failure of, for example, a proximity switch itself by generating a pulse train required for active inspection only while the proximity switch is not damped and enabling an inspection circuit to guide a response current only during the detection in non-failure state. CONSTITUTION: An oscillator 7 with two terminals is connected to an inspection circuit 1. One terminal of the oscillator 7 is connected to an input terminal A of a control circuit 4 and the other terminal is connected to an output terminal D of a damping circuit 2. An integrated circuit 5 of the circuit 4 has an input terminal A and an output terminal B and a mono-flop circuit 6 and a circuit network 8 are connected to the output terminal B. The circuit 6 has an output terminal C of the circuit 4 and the output terminal C and the circuit 2 are connected. The circuit network 8 is used as the output terminals of the circuit 4 and the circuit 1 as well as a terminal at the output terminal B of the circuit 5 and the two output terminals are connected to the input terminal of an evaluation circuit 3. In the circuit 3, for example, a load 9 is connected in series and the load 9 is connected to an input terminal E of the circuit 3. The second input terminal E is connected to the negative electrode of a DC voltage generated by a power supply part 14 and the circuit 3 is connected to a load circuit 15.</p> |
