| 摘要 |
PURPOSE:To attain the accurate range setting by providing a coupling coil coupled freely magnetically with a detction coil. CONSTITUTION:When a range setting switch 32 is turned on or an L signal is impressed to a terminal 31, a transistor (TR) Q41 is turned on, the level of a node (a) goes to H, and points A,B of an automatic bridge 41 are shortcircuited equivalently. Thus, a voltage induced in the coupling coil L41 is flowed through a load resistor R45 as a current, a loss is caused in the detection coil L11 coupled magnetically with the coil L41 to decrease the conductance of the coil L11 thereby weakening the oscillation. An object to be sensed in this state is placed at a scheduled passing location, a proximity switch 1 is approached to the object to be detected until the oscillation circuit 10 stops the oscillation and the object to be sensed is sensed, and the switch 1 is fixed. Thus, the accurate range setting of the proximity switch whose oscillating state is changed due to temperature is set.
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