INDUCTANCE DETECTOR Russian patent published in 2009 - IPC G01R29/12 

FIELD: physics, measurement.

SUBSTANCE: invention may be used as current or proximity sensor. Inductance sensor comprises generator (1) of periodic pulses, the first resistor (2), the first diode (3), the first capacitor (4), the second resistor (5), supply bus (6), n-p-n transistor (7), the third resistor (8), the fourth resistor (9), resonant LC-circuit (10), integrating RC-chain (11), the second capacitor (12), the second diode (13), operational amplifier (14), outlet (15) of operational amplifier (14). Outlet of periodic pulse generator (1) is connected to the first outlet of the first resistor (2). Cathode of the first diode (3) via the first capacitor (4) is connected to common bus, to which the first outlet of the second resistor is connected (5). Emitter of n-p-n transistor (7) is connected to common bus, and collector - via the third resistor (8) to supply bus (6). Inlet of operational amplifier (14) is connected to the second outlet of the second resistor (5) and outlet of integrating RC-chain (11), inlet of which is connected to cathode of the first diode (3). Anode of the first diode (3) is connected to the first outlet of resonant LC-circuit (10) and via the second capacitor (12) with collector of n-p-n transistor (7). Base of n-p-n transistor (7) is connected with the second outlet of the first resistor (2). The second outlet of resonant LC-circuit (10) is connected via the fourth resistor (9) with supply bus (6) and anode of the second diode (13), cathode of which is connected to common bus.

EFFECT: increased stability at simultaneous increase of outlet signal amplitude and unification of inductance sensor, which is achieved by newly introduced compensation circuits, bipolar remagnetisation and serviceability with different types of resonant LC-circuits.

3 cl, 5 dwg