CN214707674U

CN214707674U - Speed-limiting proximity switch

Info

Publication number: CN214707674U
Application number: CN202120958665.9U
Authority: CN
Inventors: 叶帆; 王源平
Original assignee: Suns Electric Zhangzhou Co ltd
Current assignee: Suns Electric Zhangzhou Co ltd
Priority date: 2021-05-07
Filing date: 2021-05-07
Publication date: 2021-11-12
Anticipated expiration: 2031-05-07

Abstract

The utility model relates to a speed-limiting proximity switch, which comprises a speed-limiting switch circuit and a packaging shell thereof, wherein the packaging shell is provided with an induction magnetic tank, a power supply positive input end BN, a control output end WH and a control output end BK, and the speed-limiting switch circuit comprises a voltage stabilizing module, an oscillating circuit, an amplifying and shaping filter circuit, a signal processing circuit and an impedance output circuit which are connected in sequence; the voltage stabilizing module is connected to a power supply positive input end BN, and the oscillating circuit is connected with an LC oscillator used for sensing metal objects. The utility model discloses a proximity switch adopts the impedance output form, utilizes the electrical signal to change impedance output circuit's resistance parameter to can effectively, succinctly make the electric current of exporting to the equipment control end keep at predetermined fixed value, play the speed limit effect.

Description

Speed-limiting proximity switch

Technical Field

The utility model relates to an electronic switch field specifically indicates to have a speed limit type proximity switch.

Background

The proximity switch is a position switch which can be operated without mechanical direct contact with a moving part, and when the sensing surface of the object proximity switch reaches an action distance, the switch can be actuated without mechanical contact and any pressure, so that a direct current electric appliance is driven or a control instruction is provided for a PLC device and the like. The positioning precision, the operating frequency, the service life, the convenience of installation and adjustment and the applicability to severe environment are far higher than those of a common mechanical travel switch, so that the travel switch is widely applied to the industries of machine tools, metallurgy, chemical engineering, light spinning, printing and the like.

Most of the output modes of the proximity switches in the current market are switch type output or linear output, and preset constant value output cannot be achieved; for some special devices, the current input value of the control terminal of the device usually has a certain range requirement, so most of the proximity switches in the market are usually connected with the devices after additional adjustment, which is time-consuming and labor-consuming.

The utility model discloses the purpose of research is to the problem design speed limit type proximity switch that foretell prior art exists.

SUMMERY OF THE UTILITY MODEL

To the problem that above-mentioned prior art exists, the utility model provides a speed limit type proximity switch can effectively solve the problem that above-mentioned prior art exists.

The technical scheme of the utility model is that:

a speed-limiting proximity switch comprises a speed-limiting switch circuit and a packaging shell thereof, wherein an induction magnetic tank, a power supply positive input end BN, a control output end WH and a control output end BK are arranged on the packaging shell, and the speed-limiting switch circuit comprises a voltage stabilizing module, an oscillating circuit, an amplifying, shaping and filtering circuit, a signal processing circuit and an impedance output circuit which are sequentially connected; the voltage stabilizing module is connected to a power supply positive input end BN, and the oscillating circuit is connected with an LC oscillator for sensing metal objects; the impedance output circuit comprises an impedance output loop A and an impedance output loop B, the input ends of the impedance output loop A and the impedance output loop B are connected to the output end Q3-B of the signal processing circuit, and the output ends of the impedance output loop A and the impedance output loop B are respectively connected to the control output end BK and the control output end WH; the impedance output loop A comprises an NPN triode Q4, a resistor R23, a resistor R24 and a resistor R25; the impedance output loop B comprises an NPN triode Q2, a resistor R27, a resistor R28 and a resistor R29.

Furthermore, the power supply positive input end BN, the impedance output loop a, and the impedance output loop B are all connected with a transient suppression diode for surge protection, and the power supply positive input end BN is also connected with a work indicator lamp circuit.

Furthermore, two ends of a resistor R23 in the impedance output loop a are respectively connected to a base of an NPN triode Q4 and an output terminal Q3-B of the signal processing circuit, a collector of the NPN triode Q4 is connected to the resistor R24, the other end of the resistor R24, which is not connected to the NPN triode Q4, is connected to the resistor R25 and the control output terminal BK, and the resistor R25 and the control output terminal BK are arranged in parallel; the resistor R25 and the NPN triode Q4 are both connected to the negative electrode of the power supply.

Furthermore, two ends of a resistor R27 in the impedance output loop B are respectively connected to the base of the NPN triode Q2 and the output terminal Q3-B of the signal processing circuit, the collector of the NPN triode Q2 is connected to the resistor R28, the other end of the resistor R28, which is not connected to the NPN triode Q2, is connected to the resistor R29 and the control output terminal WH, and the resistor R29 and the control output terminal WH are arranged in parallel; the resistor R29 and the NPN triode Q2 are both connected to the negative electrode of the power supply.

The technical scheme has the following technical effects:

the proximity switch designed by the utility model adopts an impedance output form, and utilizes an electrical signal to change resistance parameters of an impedance output loop A and an impedance output loop B, thereby effectively and simply leading the current output to the equipment control end to approach to an expected fixed value and playing a speed limiting effect; secondly, the resistance value of the impedance output circuit can be adjusted or replaced according to the current input requirement of the equipment, so that customized resistance value output can be realized, and the device is flexible and wide in application range.

Drawings

Fig. 1 is a schematic block diagram of the present invention.

Fig. 2 is a circuit schematic diagram of the speed limit switch circuit.

Fig. 3 is a circuit schematic diagram of the voltage stabilizing module and the working indicator lamp circuit.

Fig. 4 is a circuit schematic of an oscillating circuit and an LC oscillator.

Fig. 5 is a schematic circuit diagram of the amplification shaping filter circuit.

Fig. 6 is a circuit schematic of the signal processing circuit.

Fig. 7 is a schematic circuit diagram of the impedance output circuit a and the impedance output circuit B.

Detailed Description

To facilitate understanding of those skilled in the art, the structure of the present invention will now be described in further detail with reference to the following examples:

referring to fig. 1 to 7, a speed-limiting proximity switch includes a speed-limiting switch circuit and a package housing (not shown) thereof, the package housing is provided with an induction magnetic tank, a power supply positive input end BN, a control output end WH and a control output end BK, and the speed-limiting switch circuit includes a voltage stabilizing module, an oscillating circuit, an amplifying, shaping and filtering circuit, a signal processing circuit and an impedance output circuit, which are connected in sequence; the voltage stabilizing module is connected to a power supply positive input end BN, and the oscillating circuit is connected with an LC oscillator for sensing metal objects; the impedance output circuit comprises an impedance output loop A and an impedance output loop B, the input ends of the impedance output loop A and the impedance output loop B are connected to the output end Q3-B of the signal processing circuit, and the output ends of the impedance output loop A and the impedance output loop B are respectively connected to the control output end BK and the control output end WH; the impedance output loop A comprises an NPN triode Q4, a resistor R23, a resistor R24 and a resistor R25; the impedance output loop B comprises an NPN triode Q2, a resistor R27, a resistor R28 and a resistor R29.

In this embodiment, the power supply positive input terminal BN on the package casing is used to connect the power supply positive, and the voltage stabilizing module is used to convert the input voltage to a constant voltage stable state; the control output end WH and the control output end BK are used for being in butt joint with control equipment; the LC oscillator is arranged on the induction magnetic tank of the packaging shell and used for detecting whether a detected metal object approaches the induction magnetic tank or not and changing the output parameters of the oscillating circuit, and the amplifying, shaping and filtering circuit and the signal processing circuit are used for further processing the output signal of the oscillating circuit and outputting the processed signal to the impedance output circuit; the impedance output circuit changes the resistance parameter of the impedance output circuit according to the type of the input signal, and keeps constant value output under the condition that the input signal is not changed, thereby playing the function of speed limitation.

Specifically, the power supply positive input end BN, the impedance output loop a, and the impedance output loop B are all connected with a transient suppression diode for surge protection, and the power supply positive input end BN is further connected with a work indicator lamp circuit. In this embodiment, the model of the transient suppression diode is SMAJ16 CA; the working indicator light circuit is used for prompting the working state of the switch.

Specifically, two ends of a resistor R23 in the impedance output loop a are respectively connected to a base of an NPN triode Q4 and an output terminal Q3-B of the signal processing circuit, a collector of the NPN triode Q4 is connected to the resistor R24, the other end of the resistor R24, which is not connected to the NPN triode Q4, is connected to the resistor R25 and the control output terminal BK, and the resistor R25 and the control output terminal BK are arranged in parallel; the resistor R25 and the NPN triode Q4 are both connected to the negative electrode of the power supply.

In this embodiment, when the magnetic induction tank does not induce a metal object, the output terminal Q3-B of the signal processing circuit fails to obtain a voltage for turning on the NPN triode Q4, and theoretically, the internal resistance of the NPN triode Q4 at this time is infinite; therefore, the control output BK can only form a loop to the negative pole of the power supply through the resistor R25. Therefore, the overall output impedance is larger and is about equal to the resistance value 510 Ω of the resistor R25.

When a metal object approaches the induction magnetic tank, the output end Q3-B of the signal processing circuit obtains a voltage for conducting the NPN triode Q4, and the internal resistance of the NPN triode Q4 is about zero at the moment; therefore, the control output BK forms a parallel resistor to the negative pole of the power supply through the resistor R25, the resistor R24 and the NPN transistor Q4. Therefore, the overall output impedance is low at this time, which is about 122 Ω.

Specifically, two ends of a resistor R27 in the impedance output loop B are respectively connected to a base of an NPN triode Q2 and an output terminal Q3-B of the signal processing circuit, a collector of the NPN triode Q2 is connected to the resistor R28, the other end of the resistor R28, which is not connected to the NPN triode Q2, is connected to the resistor R29 and a control output terminal WH, and the resistor R29 and the control output terminal WH are arranged in parallel; the resistor R29 and the NPN triode Q2 are both connected to the negative electrode of the power supply.

In this embodiment, when the magnetic induction tank does not induce a metal object, the output terminal Q3-B of the signal processing circuit fails to obtain a voltage for turning on the NPN triode Q2, and theoretically, the internal resistance of the NPN triode Q2 at this time is infinite; therefore, at this time, the control output terminal WH can only form a loop to the negative electrode of the power supply through the resistor R29, so that the overall output impedance is relatively large and is approximately equal to the resistance value 16K Ω of the resistor R29.

When a metal object approaches the induction magnetic tank, the output end Q3-B of the signal processing circuit obtains a voltage for conducting the NPN triode Q2, and the internal resistance of the NPN triode Q2 is about zero at the moment; therefore, the control output terminal WH forms a parallel resistor to the negative electrode of the power supply through the resistor R29, the resistor R28 and the NPN transistor Q2 to form a loop. Therefore, the overall output impedance is small at this time, approximately 940 Ω.

The utility model discloses the theory of operation:

the LC oscillator is arranged on the induction magnetic tank of the packaging shell, when a measured metal object is close to the induction magnetic tank, the eddy current of the LC oscillator can be changed, so that the parameter of the whole oscillation circuit is changed, and the output signal of the oscillation circuit is changed; the output signal of the oscillation circuit is processed by the amplifying, shaping and filtering circuit and the signal processing circuit in sequence, and then is transmitted to the impedance output loop A and the impedance output loop B from the output end Q3-B of the signal processing circuit. The impedance output loop A and the impedance output loop B can change the conduction state of the corresponding NPN triode Q4 or NPN triode Q2 according to the input voltage of the output end Q3-B of the signal processing circuit, so that the resistance parameter of the impedance output loop A and the impedance output loop B is changed, and the resistance parameter can be kept constant in a certain input voltage range due to the characteristics of the NPN triodes, so that the current output can obtain the speed limiting effect. And the preset resistance value can be simply and quickly adjusted by modifying the resistance value of the resistor in the impedance output circuit, so that customized output is realized according to different access devices.

The above is only the preferred embodiment of the present invention, and all the equivalent changes and modifications made within the scope of the claims of the present invention should belong to the scope of the present invention.

Claims

1. The utility model provides a speed limit type proximity switch, includes speed limit switch circuit and packaging shell, be equipped with the response magnetic vessel on the packaging shell, power supply positive input BN, control output WH and control output BK, its characterized in that: the speed-limiting switch circuit comprises a voltage stabilizing module, an oscillating circuit, an amplifying, shaping and filtering circuit, a signal processing circuit and an impedance output circuit which are connected in sequence; the voltage stabilizing module is connected to a power supply positive input end BN, and the oscillating circuit is connected with an LC oscillator for sensing metal objects; the impedance output circuit comprises an impedance output loop A and an impedance output loop B, the input ends of the impedance output loop A and the impedance output loop B are connected to the output end Q3-B of the signal processing circuit, and the output ends of the impedance output loop A and the impedance output loop B are respectively connected to the control output end BK and the control output end WH; the impedance output loop A comprises an NPN triode Q4, a resistor R23, a resistor R24 and a resistor R25; the impedance output loop B comprises an NPN triode Q2, a resistor R27, a resistor R28 and a resistor R29.

2. A speed-limiting proximity switch as defined in claim 1, wherein: the power supply positive input end BN, the impedance output loop A and the impedance output loop B are all connected with a transient suppression diode used for surge protection, and the power supply positive input end BN is further connected with a work indicator lamp circuit.

3. A speed-limiting proximity switch as defined in claim 2, wherein: two ends of a resistor R23 in the impedance output loop A are respectively connected to a base of an NPN triode Q4 and an output end Q3-B of the signal processing circuit, a collector of the NPN triode Q4 is connected to a resistor R24, the other end, which is not connected to the NPN triode Q4, of the resistor R24 is connected to the resistor R25 and the control output end BK, and the resistor R25 and the control output end BK are arranged in parallel; the resistor R25 and the NPN triode Q4 are both connected to the negative electrode of the power supply.

4. A speed-limiting proximity switch as defined in claim 3, wherein: two ends of a resistor R27 in the impedance output loop B are respectively connected to a base of an NPN triode Q2 and an output end Q3-B of the signal processing circuit, a collector of the NPN triode Q2 is connected to a resistor R28, the other end of the resistor R28, which is not connected to the NPN triode Q2, is connected to the resistor R29 and a control output end WH, and the resistor R29 and the control output end WH are arranged in parallel; the resistor R29 and the NPN triode Q2 are both connected to the negative electrode of the power supply.