CN112240778A

CN112240778A - Distance detection learning type inductive sensor

Info

Publication number: CN112240778A
Application number: CN202011039586.4A
Authority: CN
Inventors: 伍成强; 陈国祥
Original assignee: Hunan Zenlink Sensor Co ltd
Current assignee: Hunan Zhunlian Instrument Co ltd
Priority date: 2020-09-28
Filing date: 2020-09-28
Publication date: 2021-01-19
Anticipated expiration: 2040-09-28
Also published as: CN112240778B

Abstract

The invention discloses a detection distance learning type inductive sensor which comprises a plastic front plug, an inductive coil, a magnetic core, a PCB fixing sheet, a main circuit PCB board, a copper shell, a touch key PCB board, a touch key silica gel cap, a copper tail plug and a four-pin female plug. Therefore, the types of the sensors can be greatly reduced during production and type selection by users, and the production cost and the types of stock of the users are reduced. Meanwhile, the detection distance of the finished product can be adjusted through a key learning function, so that the problem that the product is unqualified due to the detection distance error of the sensor is fundamentally solved.

Description

Distance detection learning type inductive sensor

Technical Field

The invention relates to the technical field of sensors, in particular to a learning type inductive sensor for detecting distance.

Background

An inductance type sensor belongs to a position sensor for switching value output. It is composed of LC high-frequency oscillator and amplifying circuit, and when a metal object is close to the oscillating sensing head which can generate alternating electromagnetic field, it can generate eddy current in the object. The eddy current reacts on the inductive sensor, so that the oscillation capacity of the inductive sensor is attenuated, parameters of an internal circuit are changed, whether a metal object is close to the inductive sensor or not is identified, and the on-off of the switch is controlled. It can detect whether there is an object approaching within a certain distance (several millimeters to tens of millimeters). When the object approaches the preset distance, the 'action' signal can be sent out. The automatic control system can be widely applied to the industries of machine tools, metallurgy, chemical engineering, light spinning, printing and the like, and can be applied to stroke limit, product counting of production lines and the like in an automatic control system. The inductive sensor is not in contact with a measured object, does not generate mechanical wear and fatigue damage, and has the characteristics of long service life, quick response, no contact, no spark, no noise, moisture protection, dust protection, better explosion-proof performance, strong output signal load capacity, safety and reliability.

At present, in the industry of inductive sensors, the types of the sensors are various. Different detection distances are divided according to the detection distance; the output mode is divided into NPN type or PNP type; according to the action form it has normally-open or normally-closed output. Therefore, the problems of multiple sensor types, high production switching cost, difficult type selection of users and the like are caused.

The detection distance of the traditional inductive sensor is a fixed value. The product debugging, test, encapsulating all can cause great error to the measuring distance of product in process of production, and some errors too big can not reach qualified standard still can cause the product to scrap.

Disclosure of Invention

The present invention is directed to a learning-type inductive sensor for detecting distance, so as to solve the above-mentioned problems.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a detection distance study type inductive sensor, stopper, inductance coils, magnetic core, PCB stationary blade, main circuit PCB board, copper casing before including the plastic, dab button PCB board, dab the button, dab button silica gel cap, copper tail plug, four-pin female plug, the main circuit PCB board is installed inside the copper casing, and the one end of copper casing is equipped with the PCB stationary blade, and the opposite side of PCB stationary blade is equipped with the magnetic core, is equipped with inductance coils on the magnetic core, and the one end of copper casing is equipped with the stopper before the plastic, and the other end of copper casing is equipped with the copper tail plug, and four-pin female plug is connected to the copper tail plug other end, still is equipped with on the copper casing and dabs the button, and the below of dabbing the button is equipped with dabs button PCB board, and the top of.

As a further technical scheme of the invention: the main circuit PCB board comprises an MCU microprocessor, a 5V voltage stabilizing circuit, an 8V voltage stabilizing circuit, an LC oscillating circuit, an integrating circuit, a voltage follower, a temperature compensation circuit, an output control circuit, a PNP output short circuit/overload protection circuit and an NPN output short circuit/overload protection circuit, wherein the LC oscillating circuit is respectively connected with the 8V voltage stabilizing circuit and the integrating circuit, the 8V voltage stabilizing circuit is also respectively connected with the 5V voltage stabilizing circuit, the PNP output short circuit/overload protection circuit and the output control circuit, the 5V voltage stabilizing circuit is also connected with the voltage follower and the MCU microprocessor, the MCU microprocessor is also respectively connected with the output control circuit and the temperature compensation circuit, the output control circuit is also respectively connected with the PNP output short circuit/overload protection circuit and the NPN output short circuit/overload protection circuit, and the integrating circuit is.

As a further technical scheme of the invention: the PNP output short circuit/overload protection circuit includes a twenty-second resistor R26, a fourth PNP transistor T5, a twenty-third resistor R31, and an eighth NPN transistor T8, wherein an input terminal of the twenty-second resistor R26 is electrically connected to a base of the fourth PNP transistor T5 and to a PNP output terminal of the output control circuit, an output terminal of the twenty-second resistor R26 is electrically connected to a VCC power supply and to a power input terminal a, an emitter of the fourth PNP transistor T5 is electrically connected to a VCC power supply, a collector of the fourth PNP transistor T5 is electrically connected to an input terminal of the twenty-third resistor R31, an output terminal of the twenty-third resistor R31 is electrically connected to a base of the eighth NPN transistor T8, a collector of the eighth NPN transistor T8 is electrically connected to a pin 3 of the MCU microprocessor, and an emitter of the eighth NPN transistor T8 is grounded.

As a further technical scheme of the invention: the NPN output short circuit/overload protection circuit includes a twenty-fourth resistor R37 and a ninth NPN transistor T12, wherein an input terminal of the twenty-fourth resistor R37 and a base of the ninth NPN transistor T12 are electrically connected to the NPN output terminal of the output control circuit, an emitter of the ninth NPN transistor T12 is electrically connected to the pin 3 of the MCU microprocessor, and an emitter of the ninth NPN transistor T12 is grounded and connected to the power input terminal C.

As a further technical scheme of the invention: the 5V voltage stabilizing circuit comprises a switching diode D5, a voltage stabilizing diode D6, a twenty-fifth resistor R28, a seventh capacitor C10, a tenth NPN triode T6, a twenty-sixth resistor R33, a controllable precision voltage stabilizing source T10, a twenty-seventh resistor R34, a twenty-eighth resistor R36 and an eighth capacitor C9, wherein the input end of the switching diode D5 is electrically connected with the power supply input end A, the output end of the switching diode D5, the input end of the voltage stabilizing diode D6 and the input end of the twenty-fifth resistor R28 are connected to a +8V voltage stabilizing circuit, the output end of the voltage stabilizing diode D6 is grounded, the output end of the twenty-fifth resistor R28 and the input end of the twenty-sixth resistor R33 are electrically connected with the input end of the seventh capacitor C10 and the collector of the tenth NPN triode T6, the output end of the seventh capacitor C10 is grounded, the reference pole of the controllable precision voltage stabilizing source T10 is electrically connected with the input end of the twenty-seventh resistor R34 and the input end of, an output end of the twenty-seventh resistor R34 is electrically connected to an emitter of the tenth NPN transistor T6 and to an input end of the eighth capacitor C9, and an output end of the twenty-eighth resistor R36 and an output end of the eighth capacitor C9 are grounded.

As a further technical scheme of the invention: the 8V voltage stabilizing circuit comprises a twenty-ninth resistor R29, a ninth capacitor C8, a 78L08 three-terminal voltage stabilizing chip IC4 and a tenth capacitor C7, wherein the input end of the twenty-ninth resistor R29 is electrically connected with a power supply VDD, the output end of the twenty-ninth resistor R29 is electrically connected to the input end of the ninth capacitor C8 and the input end of the 78L08 three-terminal voltage stabilizing chip IC4, the output end of the ninth capacitor C8 is grounded with the ground end of the 78L08 three-terminal voltage stabilizing chip IC4, the output end of the 78L08 three-terminal voltage stabilizing chip IC4 is electrically connected to the input end of the tenth capacitor and the +8V power supply output, and the output end of the tenth capacitor C7 is grounded.

Compared with the prior art, the invention has the beneficial effects that: according to the invention, different detection distance adjustments, NPN and PNP output mode switching and normally open and normally closed action mode switching can be realized through a key learning function only by an inductive sensor. Therefore, the types of the sensors can be greatly reduced during production and type selection by users, and the production cost and the types of stock of the users are reduced. Meanwhile, the detection distance of the finished product can be adjusted through a key learning function, so that the problem that the product is unqualified due to the detection distance error of the sensor is fundamentally solved.

Drawings

FIG. 1 is a schematic diagram of a detection distance learning type inductive sensor.

Fig. 2 is a block diagram of a sensor circuit.

Fig. 3 is a sensor circuit diagram.

In the figure: the plastic rubber front plug comprises a plastic rubber front plug 1, an inductance coil 2, a magnetic core 3, a PCB fixing sheet 4, a main circuit PCB 5, a copper shell 6, a light touch key PCB 7, a light touch key 8, a light touch key silica gel cap 9, a copper tail plug 10 and a four-pin female plug 11.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1: referring to fig. 1-3, a learning-type inductive sensor for detecting distance comprises a plastic front plug 1, an inductive coil 2, a magnetic core 3, a PCB fixing plate 4, a main circuit PCB 5, a copper shell 6, a touch key PCB 7, a touch key 8, a touch key silicone cap 9, a copper tail plug 10, and a four-pin female plug 11, the main circuit PCB board 5 is installed inside copper casing 6, the one end of copper casing 6 is equipped with PCB stationary blade 4, the opposite side of PCB stationary blade 4 is equipped with magnetic core 3, be equipped with inductance coils 2 on the magnetic core 3, the one end of copper casing 6 is equipped with stopper 1 before the plastic, the other end of copper casing 6 is equipped with copper tail stopper 10, four-pin female plug 11 is connected to the copper tail stopper 10 other end, still be equipped with on the copper casing 6 and dabble button 8, the below that dabs button 8 is equipped with dabs button PCB board 7, the top that dabs button 8 is equipped with dabs button silica gel cap 9.

As shown in fig. 2, the main circuit PCB board 5 includes an MCU microprocessor, a 5V voltage stabilizing circuit, an 8V voltage stabilizing circuit, an LC oscillating circuit, an integrating circuit, a voltage follower, a temperature compensating circuit, an output control circuit, a PNP output short circuit/overload protection circuit and an NPN output short circuit/overload protection circuit, the LC oscillating circuit is connected to the 8V voltage stabilizing circuit and the integrating circuit, the 8V voltage stabilizing circuit is connected to the 5V voltage stabilizing circuit, the PNP output short circuit/overload protection circuit and the output control circuit, the 5V voltage stabilizing circuit is connected to the voltage follower and the MCU microprocessor, the MCU microprocessor is connected to the output control circuit and the temperature compensating circuit, the output control circuit is connected to the PNP output short circuit/overload protection circuit and the NPN output short circuit/overload protection circuit, and the integrating circuit is connected to the voltage follower. The 5V power supply provided by the 5V power supply voltage stabilizing circuit provides stable voltage for the MCU microprocessor and the voltage follower, the 8V power supply provided by the 8V power supply voltage stabilizing circuit provides stable voltage for LC oscillation through a first voltage providing circuit and a second voltage providing circuit in the LC oscillating circuit, and provides feedback signals for the oscillating circuit through feeding back a fourth NPN triode T2B and a fifth NPN triode T2A, so that the LC oscillation is more stable; the LC oscillating circuit sends an oscillating signal to the integrating circuit, the integrating circuit integrates continuous sine waves generated by the oscillating circuit and outputs the continuous sine waves to the equidirectional end of the voltage follower circuit comparator, an output end signal of the voltage follower circuit comparator IC2 is connected to an AD signal sampling end of the MCU microprocessor and is compared with an internal threshold value set value of the MCU microprocessor, and therefore the corresponding current conducting circuit is controlled and output to enable an output end circuit to be conducted to obtain a corresponding current value, and the external PLC controls the output end circuit to obtain a corresponding distance value. In the embodiment of the application, short circuit or overload protection is performed on each device through the short circuit and overload protection circuit, and the stability of output current and the stability of LC oscillation are further ensured through the voltage stabilizing circuit, so that the detection accuracy of the proximity switch is improved. In addition, in the embodiment of the application, the proximity switch can be subjected to temperature software compensation through the temperature compensation circuit, and also can be subjected to temperature hardware compensation through the eighth thermistor R23, so that the temperature performance of the proximity switch is improved, the proximity switch can be normally used in high-temperature and low-temperature environments, and the detection accuracy of the proximity switch is ensured.

Example 2: on the basis of example 1: as shown in fig. 3, the PNP output short/overload protection circuit includes a twenty-second resistor R26, a fourth PNP transistor T5, a twenty-third resistor R31, and an eighth NPN transistor T8, wherein an input terminal of the twenty-second resistor R26 is electrically connected to a base of the fourth PNP transistor T5 and to a PNP output terminal of the output control circuit, an output terminal of the twenty-second resistor R26 is electrically connected to a VCC power supply and to a power input terminal a, an emitter of the fourth PNP transistor T5 and to a VCC power supply, a collector of the fourth PNP transistor T5 is electrically connected to an input terminal of the twenty-third resistor R31, an output terminal of the twenty-third resistor R31 is electrically connected to a base of the eighth NPN transistor T8, a collector of the eighth NPN transistor T8 is electrically connected to pin 3 of the MCU microprocessor, and an emitter of the eighth NPN transistor T8 is grounded.

As shown in the lower left region of fig. 3, the NPN output short/overload protection circuit includes a twenty-fourth resistor R37 and a ninth NPN transistor T12, wherein an input terminal of the twenty-fourth resistor R37 and a base of the ninth NPN transistor T12 are electrically connected to the NPN output terminal of the output control circuit, an emitter of the ninth NPN transistor T12 is electrically connected to the pin 3 of the MCU microprocessor, and an emitter of the ninth NPN transistor T12 is grounded and connected to the power input terminal C.

In the area shown in the right middle of fig. 3, the 5V regulator circuit includes a switching diode D5, a zener diode D6, a twenty-fifth resistor R28, a seventh capacitor C10, a tenth NPN transistor T6, a twenty-sixth resistor R33, a controllable precision regulator T10, a twenty-seventh resistor R34, a twenty-eighth resistor R36, and an eighth capacitor C9, wherein an input terminal of the switching diode D5 is electrically connected to the power input terminal a, an output terminal of the switching diode D5, an input terminal of the zener diode D6, and an input terminal of the twenty-fifth resistor R28 are connected to the +8V regulator circuit, an output terminal of the zener diode D6 is grounded, an output terminal of the twenty-fifth resistor R28, an input terminal of the twenty-sixth resistor R33, an input terminal of the seventh capacitor C10, and a collector of the tenth NPN transistor T6 are electrically connected, an output terminal of the seventh capacitor C10 is grounded, a reference terminal of the controllable regulator T10, a twenty-eighth resistor R34, an input terminal of the controllable precision regulator T36, and a An output terminal of the twenty-seventh resistor R34 is electrically connected to an emitter of the tenth NPN transistor T6 and to an input terminal of the eighth capacitor C9, and an output terminal of the twenty-eighth resistor R36 and an output terminal of the eighth capacitor C9 are grounded.

As shown in the right lower region of fig. 3, the 8V voltage stabilizing circuit includes a twenty-ninth resistor R29, a ninth capacitor C8, a 78L08 three-terminal voltage stabilizing chip IC4 and a tenth capacitor C7, wherein an input terminal of the twenty-ninth resistor R29 is electrically connected to the power supply VDD, an output terminal of the twenty-ninth resistor R29 is electrically connected to an input terminal of the ninth capacitor C8 and to an input terminal of the 78L08 three-terminal voltage stabilizing chip IC4, an output terminal of the ninth capacitor C8 is grounded to a ground terminal of the 78L08 three-terminal voltage stabilizing chip IC4, an output terminal of the 78L08 three-terminal voltage stabilizing chip IC4 is electrically connected to an input terminal of the tenth capacitor and to a +8V power supply output, and an output terminal of the tenth capacitor C7 is grounded.

As shown in the middle of fig. 3, the integrating circuit includes a third capacitor C6, a ninth resistor R13 and a tenth resistor R24, an output terminal of the ninth resistor R13 is connected to input terminals of a third capacitor C6 and a tenth resistor R24 which are connected in parallel, respectively, wherein output terminals of the third capacitor C6 and the tenth resistor R24 are grounded, and input terminals of the third capacitor C6 and the tenth resistor R24 are electrically connected to the voltage follower circuit.

As shown in the middle of fig. 3, the voltage follower circuit is composed of an operational amplifier IC2, the input ends of the third capacitor C6 and the tenth resistor R24 of the integrating circuit are electrically connected to the equidirectional input end of the operational amplifier IC2 of the voltage follower circuit, and the output end of the operational amplifier IC2 is connected to the 15 th pin of the MCU microprocessor. And the 5 th pin of the operational amplifier IC2 is electrically connected with a +8V power supply, and the 2 nd pin of the operational amplifier IC2 is grounded.

As shown in the upper right region of fig. 3, the MCU microprocessor circuit includes a microprocessor IC1, an eleventh resistor R8, a fifth capacitor C3, a fourth capacitor C1, a fifth capacitor C3, a sixth capacitor C4, a twelfth resistor R7, a thirteenth resistor R6, a fourteenth resistor R5, a fifteenth resistor R4, and a programming interface P1, wherein the 1 st pin of the MCU microprocessor is electrically connected to the input terminals of the eleventh resistor R8 and the fifth capacitor C3, the output terminal of the eleventh resistor R8 is electrically connected to the +5V power supply, the output terminal of the fifth capacitor C3 is grounded, the 3 rd pin of the MCU microprocessor is electrically connected to the PNP output short-circuit overload protection circuit and the NPN output short-circuit overload protection circuit, the 4 th pin and the 10 th pin of the MCU microprocessor are grounded, the 5 th pin of the MCU microprocessor is electrically connected to the input terminal of the fourth capacitor C1, the output terminal of the fourth capacitor C1 is grounded, and the 5 th pin of the MCU microprocessor is electrically connected to the PNP output terminal of the, The 6 th pin and the 9 th pin of the MCU microprocessor are electrically connected with a +5V power supply, the 15 th pin of the MCU microprocessor is electrically connected to the voltage follower circuit, the 16 th pin of the MCU microprocessor is electrically connected to the temperature compensation circuit, the 17 th pin of the MCU microprocessor is electrically connected to the input end of a tact key S1, the output end of the tact key S1 is grounded, the 21 st pin of the MCU microprocessor is electrically connected to the input end of a twelfth resistor R7, the output end of the twelfth resistor R7 is electrically connected with the cathode of an indicator lamp D4, the anode of the indicator lamp D4 is electrically connected with a +5V power supply, the 22 nd pin of the MCU microprocessor is electrically connected to the input end of a thirteenth resistor R6, the output end of the thirteenth resistor R6 is electrically connected with the cathode of an indicator lamp D3, the anode of the indicator lamp D3 is electrically connected with a +5V power supply, the 23 rd pin of the MCU microprocessor is, an output end of the twelfth resistor R5 is electrically connected with a cathode of an indicator light D2, an anode of the indicator light D2 is electrically connected with a +5V power supply, a 24 th pin of the MCU microprocessor is electrically connected with an input end of the fifteenth resistor R4, an output end of the thirteenth resistor R4 is electrically connected with a cathode of the indicator light D1, an anode of the indicator light D1 is electrically connected with a +5V power supply, and a 2 nd pin, an 8 th pin, an 11 th pin, a 12 th pin, a 13 th pin, a 14 th pin, a 15 th pin, an 18 th pin, a 19 th pin, a 20 th pin, a 25 th pin, a 27 th pin, a 28 th pin, a 29 th pin and a 32 th pin of the MCU microprocessor are vacant. The 1 st pin of a programming interface P1 of the MCU microprocessor is electrically connected to the 1 st pin of the microprocessor, the 2 nd pin of a programming interface P1 of the MCU microprocessor is electrically connected to the 26 th pin of the microprocessor, the 3 rd pin of a programming interface P1 of the MCU microprocessor is electrically connected with a +5V power supply, and the 4 th pin of a programming interface P1 of the MCU microprocessor is grounded.

As shown in the rightmost area of fig. 3, the temperature compensation circuit includes a sixteenth resistor R9 and a seventeenth thermistor R10, wherein the input terminals of the sixteenth resistor R9 and the seventeenth thermistor R10 are electrically connected to the 16 th pin of the microprocessor, the output terminal of the sixteenth resistor R9 is electrically connected to the +5V power supply, and the output terminal of the seventeenth thermistor R10 is grounded.

As shown in the lower left region of fig. 3, the output control circuit includes an eighteenth resistor R32, a nineteenth resistor R30, a twentieth resistor R27, a twenty-first resistor R35, a sixth NPN transistor T9, a seventh NPN transistor T11, and a third PNP transistor T7, wherein an input terminal of the eighteenth resistor R32 is electrically connected to the 31 st pin of the MCU microprocessor, an output terminal of the eighteenth resistor R32 is electrically connected to the base terminal of the sixth NPN transistor T9, an emitter terminal of the sixth NPN transistor T9 is grounded, a collector terminal of the sixth transistor T9 is electrically connected to the input terminal of the nineteenth resistor R30, an output terminal of the nineteenth resistor R30 is electrically connected to the input terminal of the twentieth resistor R27 and the base terminal of the third NPN transistor T7, an output terminal of the twentieth resistor R27 and an emitter terminal of the third NPN transistor T7 are electrically connected to the PNP output short-circuit protection circuit, an input terminal of the twenty overload resistor R35 is electrically connected to the 30 th pin, an output end of the twenty-first resistor R35 is electrically connected to a base of the seventh NPN transistor T11, an emitter of the seventh NPN transistor T11 is electrically connected to the NPN output short-circuit overload protection circuit, and a collector of the third NPN transistor T7 and a collector of the seventh NPN transistor are electrically connected to the signal output end B.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.

Furthermore, it should be understood that although the present description refers to embodiments, not every embodiment may contain only a single embodiment, and such description is for clarity only, and those skilled in the art should integrate the description, and the embodiments may be combined as appropriate to form other embodiments understood by those skilled in the art.

Claims

1. A distance detection learning type inductive sensor comprises a plastic front plug (1), an inductive coil (2), a magnetic core (3), a PCB fixed sheet (4), a main circuit PCB (5), a copper shell (6), a touch key PCB (7), a touch key (8), a touch key silica gel cap (9), a copper tail plug (10) and a four-pin female plug (11), and is characterized in that the main circuit PCB (5) is installed inside the copper shell (6), the PCB fixed sheet (4) is arranged at one end of the copper shell (6), the magnetic core (3) is arranged at the other end of the PCB fixed sheet (4), the inductive coil (2) is arranged on the magnetic core (3), the plastic front plug (1) is arranged at one end of the copper shell (6), the copper tail plug (10) is arranged at the other end of the copper tail plug (10), the four-pin female plug (11) is connected with the other end of the copper tail plug (10), the touch key (8) is also arranged on the copper shell (6), a light touch key PCB (7) is arranged below the light touch key (8), and a light touch key silica gel cap (9) is arranged above the light touch key (8).

2. The learning inductive sensor according to claim 1, wherein the main circuit PCB (5) comprises an MCU microprocessor, a 5V voltage regulator circuit, a 8V voltage regulator circuit, an LC oscillator circuit, an integrator circuit, a voltage follower, a temperature compensation circuit, an output control circuit, a PNP output short circuit/overload protection circuit and an NPN output short circuit/overload protection circuit, the LC oscillator circuit is connected with the 8V voltage regulator circuit and the integrator circuit respectively, the 8V voltage regulator circuit is connected with the 5V voltage regulator circuit, the PNP output short circuit/overload protection circuit and the output control circuit respectively, the 5V voltage regulator circuit is connected with the voltage follower and the MCU microprocessor, the MCU microprocessor is connected with the output control circuit and the temperature compensation circuit respectively, the output control circuit is connected with the PNP output short circuit/overload protection circuit and the NPN output short circuit/overload protection circuit respectively, the integrating circuit is also connected with a voltage follower.

3. The inductive sensor of claim 2, wherein said PNP output short/overload protection circuit comprises a twenty-second resistor R26, a fourth PNP transistor T5, a twenty-third resistor R31, and an eighth NPN transistor T8, wherein said twenty-second resistor R26 input is electrically connected to the base of a fourth PNP transistor T5 and to the PNP output of the output control circuit, said twenty-second resistor R26 output is electrically connected to the emitter of a fourth PNP transistor T5 and to the VCC power supply and to the power input A, said fourth PNP transistor T5 has its collector electrically connected to the input of said twenty-third resistor R31, said twenty-third resistor R31 has its output electrically connected to the base of said eighth NPN transistor T8, said eighth NPN transistor T8 has its collector electrically connected to pin 3 of the MCU microprocessor, the emitter of the eighth NPN transistor T8 is grounded.

4. A sensed distance learning inductive sensor according to claim 2, characterized in that said NPN output short/overload protection circuit comprises a twenty-fourth resistor R37 and a ninth NPN transistor T12, wherein an input terminal of said twenty-fourth resistor R37 and a base terminal of said ninth NPN transistor T12 are electrically connected to the NPN output terminal of the output control circuit, an emitter terminal of said ninth NPN transistor T12 is electrically connected to pin 3 of the MCU microprocessor, and an emitter terminal of said ninth NPN transistor T12 is grounded and connected to the power supply input terminal C.

5. The learning inductive sensor of claim 2 wherein said 5V regulated circuit comprises a switching diode D5, a zener diode D6, a twenty-fifth resistor R28, a seventh capacitor C10, a tenth NPN transistor T6, a twenty-sixth resistor R33, a controllable precision regulator T10, a twenty-seventh resistor R34, a twenty-eighth resistor R36 and an eighth capacitor C9, wherein an input terminal of said switching diode D5 is electrically connected to the power input terminal A, an output terminal of said switching diode D5, an input terminal of said zener diode D6 and an input terminal of said twenty-fifth resistor R28 are connected to the +8V regulated circuit, an output terminal of said zener diode D6 is grounded, an output terminal of said twenty-fifth resistor R28 and an input terminal of said twenty-sixth resistor R33 are electrically connected to an input terminal of said seventh capacitor C10 and to a collector of said tenth NPN transistor T6, the output end of the seventh capacitor C10 is grounded, the reference electrode of the controllable precise voltage-stabilizing source T10 is electrically connected with the input end of a twenty-seventh resistor R34 and is connected to the input end of a twenty-eighth resistor R36, the output end of the twenty-seventh resistor R34 is electrically connected with the emitter of the tenth NPN triode T6 and is connected to the input end of an eighth capacitor C9, and the output end of the twenty-eighth resistor R36 is grounded with the output end of the eighth capacitor C9.

6. The inductive sensor of claim 2, wherein said 8V regulation circuit comprises a twenty-ninth resistor R29, a ninth capacitor C8, a 78L08 three-terminal regulation chip IC4 and a tenth capacitor C7, wherein an input terminal of said twenty-ninth resistor R29 is electrically connected to the power supply VDD, an output terminal of said twenty-ninth resistor R29 is electrically connected to an input terminal of said ninth capacitor C8 and to an input terminal of a 78L08 three-terminal regulation chip IC4, an output terminal of said ninth capacitor C8 is grounded to a ground terminal of said 78L08 three-terminal regulation chip IC4, an output terminal of said 78L08 three-terminal regulation chip IC4 is electrically connected to an input terminal of said tenth capacitor and to a +8V power supply output, and an output terminal of said tenth capacitor C7 is grounded.

7. The inductive sensor of claim 2, wherein said integration circuit comprises a third capacitor C6, a ninth resistor R13 and a tenth resistor R24, an output terminal of said ninth resistor R13 is connected to input terminals of a third capacitor C6 and a tenth resistor R24, which are connected in parallel, respectively, wherein output terminals of said third capacitor C6 and said tenth resistor R24 are grounded, and input terminals of said third capacitor C6 and said tenth resistor R24 are electrically connected to said voltage follower circuit. .