| 摘要 |
PROBLEM TO BE SOLVED: To provide a proximity switch which can prevent false detection due to the emission of external waves, and can obtain a proper detection output without reversing the detecting signals, even when the external waves are repeatedly emitted and stopped during object detection (such as during the stagnation). SOLUTION: This proximity switch has an oscillation circuit part 21 that comprises an oscillation part 25 having a resonance coil 20 and a comparator 28 which detects the change in oscillation output from the oscillation part 25 upon approach of an object and outputs an object detecting signal. This switch also has a wave detector Tr4 which detects the external waves and holding circuits SW1 and C1 which hold an input signal level from the oscillation circuit part 21 to an output circuit 22 by using the wave detecting signal detected by the wave detector Tr4.
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