| 摘要 |
The invention relates to an inductive proximity switch for detecting a metal trigger 1 in monitored region, comprising an oscillator which has a parallel resonant circuit with a sensor coil 2 for generating a high-frequency magnetic field and which has a frequency-determining capacitor 3, a current mirror circuit 4 with a number of switchable current mirrors 4n, a trimming resistor 5 for exciting the parallel resonant circuit, and an analysis unit 6 for generating a binary switch signal. The current mirror 4n which is connected in parallel to the first current mirror 4n influences the conversion ratio between the control current in the trimming resistor 5 and the resonant circuit current in the controlled circuit. The resonant circuit is provided with a constant current, and the resonant circuit amplitude influenced by the presence of the trigger 1 is analyzed by an amplitude comparator 6b. |
