Sensor anti-opening device based on inching switch

Abstract

The utility model discloses a sensor anti-opening device based on inching switches, and relates to the technical field of sensor weighing, and the device comprises a sensor, and a microcontroller, a backup power supply, a plurality of inching switches and a detection circuit which are arranged in the sensor. A plurality of inching switches are arranged on the inner side of the sensor shell; the plurality of inching switches are connected in parallel and sealed at key parts on the inner side of the sensor shell; the sealed inching switch is in contact with the sensor shell, and the sensor shell applies pressure to the inching switch; the detection circuit is respectively connected with the microcontroller, the back-up power supply and the plurality of inching switches; the microcontroller is connected with the backup power supply through a plurality of inching switches; the microcontroller determines whether the sensor shell is opened or not according to the current states of the inching switches. Through the arrangement, the cheating behavior that equipment such as a remote control device is additionally arranged in the sensor is avoided from the source, and the safety and the reliability of the sensor are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electronic weighing, in particular to a sensor anti-opening device based on a momentary switch. BACKGROUND

[0002] Digital weighing sensors have a pivotal position in the weighing sensor market due to their strong anti-interference ability, communication encryption, and anti-cheating features. Due to the pursuit of profit, some people will install remote control devices in digital weighing sensors to change the weight signal during the measurement process, indirectly change the total price of goods, and make profits, causing huge losses to enterprises and individuals. At present, the main prevention and control methods for cheating include communication protocol encryption, current detection, and data jump analysis. However, new types of remote control devices are constantly emerging, which can easily lead to improper prevention and control. Therefore, how to prevent the installation of remote control devices at the source is an urgent problem to be solved. SUMMARY

[0003] The purpose of the present application is to provide a sensor anti-opening device based on a momentary switch, which can effectively prevent the installation of remote control devices in the sensor and improve the safety and reliability of the sensor.

[0004] To achieve the above-mentioned purpose, the present application provides the following solutions:

[0005] In a first aspect, the present application provides a sensor anti-opening device based on a momentary switch, comprising:

[0006] a sensor, a microcontroller, a backup power supply, a plurality of momentary switches, and a detection circuit arranged inside the sensor;

[0007] A plurality of momentary switches are arranged inside the sensor housing; a plurality of momentary switches are sealed in key positions inside the sensor housing; the key positions include all positions that need to be disassembled when the sensor housing is disassembled;

[0008] The sealed momentary switch is in contact with the sensor housing, and the sensor housing applies pressure to the momentary switch; the current state of the momentary switch is an open state;

[0009] The detection circuit is connected to the microcontroller, the backup power supply, and a plurality of momentary switches; the detection circuit includes a main power supply;

[0010] The microcontroller is connected to the backup power supply through a plurality of momentary switches;

[0011] The microcontroller determines whether the sensor housing is opened according to the current state of a plurality of momentary switches; the current state includes an open state and a closed state;

[0012] The microcontroller determines whether the sensor shell is opened based on the backup power supply and any momentary switch in the closed state without the main power supply being turned on; the microcontroller determines whether the sensor shell is opened based on the detection circuit with the main power supply being turned on.

[0013] According to the specific embodiments provided in the application, the following technical effects are disclosed:

[0014] The application provides a sensor anti-opening device based on a momentary switch, which is provided with a backup power supply, a plurality of momentary switches, a detection circuit and a microcontroller. The plurality of parallel momentary switches are arranged at key positions on the inside of the sensor shell, and all the momentary switches are in a disconnected state in contact with the sensor shell. In this way, when the sensor shell is opened, the momentary switch is triggered to be in a closed state, and the backup power supply supplies power to the microcontroller, so that the microcontroller can timely detect that the sensor shell is opened without the main power supply being turned on. When the main power supply is turned on, the microcontroller detects whether the sensor shell is opened through the detection circuit. That is, the main power supply can detect whether the sensor shell is opened in the case that the main power supply is turned on and the case that the main power supply is not turned on, which avoids the cheating behavior of adding a remote control device in the sensor and improves the safety and reliability of the sensor. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor based on these drawings.

[0016] Figure 1 An electronic circuit diagram of the sensor anti-opening device based on a momentary switch provided in the embodiments of the application;

[0017] Figure 2 A structural schematic diagram of the sensor anti-opening device based on a momentary switch provided in the embodiments of the application;

[0018] Figure 3 A momentary switch schematic diagram of the sensor anti-opening device based on a momentary switch provided in the embodiments of the application; wherein, Figure 3 a is a closed schematic diagram of the momentary switch; Figure 3 b is a disconnected schematic diagram of the momentary switch. DETAILED DESCRIPTION

[0019] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments of the present application, all the other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of the present application.

[0020] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0021] As shown in Figure 1 and Figure 2 , the present application provides a sensor anti-opening device based on momentary switch 4, which comprises a sensor and a microcontroller 6, a backup power supply, a plurality of momentary switches 4 and a detection circuit U2 arranged inside the sensor; a plurality of momentary switches 4 are arranged on the inner side of the sensor shell 1; a plurality of momentary switches 4 are sealed in the key positions on the inner side of the sensor shell 1; the key positions include all positions that need to be disassembled when the sensor shell 1 is disassembled; the momentary switches 4 in the sealed state are in contact with the sensor shell 1, and the sensor shell 1 applies pressure to the momentary switches 4; the current state of the momentary switches 4 is an open state; the detection circuit U2 is connected with the microcontroller 6, the backup power supply and a plurality of momentary switches 4 respectively; the detection circuit U2 comprises a main power supply; the microcontroller 6 is connected with the backup power supply through a plurality of momentary switches 4; the microcontroller 6 determines whether the sensor shell 1 is opened according to the current state of a plurality of momentary switches 4; the current state includes an open state and a closed state; the microcontroller 6 determines whether the sensor shell 1 is opened based on the backup power supply and any momentary switch 4 in the closed state without connecting the main power supply; the microcontroller 6 determines whether the sensor shell 1 is opened based on the detection circuit U2 when the main power supply is connected.

[0022] Among them, Figure 2 U1 in the above-mentioned formula is the microcontroller 6.

[0023] Among them, the momentary switch 4 is pressed by the sensor shell 1, so that the current state of the momentary switch 4 is an open state. It is worth noting that the momentary switch 4 is K in Figure 3 , which is closed without external force, as shown in Figure 3 a. That is, the momentary switch 4 is a normally closed switch, so the circuit is connected. After the momentary switch 4 is subjected to external force and has a certain stroke, the two ends of the switch are separated, and the circuit is disconnected, as shown in Figure 3 b.

[0024] In some embodiments, the detection circuit U2 comprises: a P-channel field effect transistor Q1, a pull-down resistor R2, a first current-limiting resistor R1, an NPN transistor Q2, a third current-limiting resistor R4, a first Schottky diode D1, a second current-limiting resistor R3, and a second Schottky diode D2.

[0025] In some embodiments, the jog switch 4 comprises a first jog switch S1 and a second jog switch S2; the first jog switch S1 and the second jog switch S2 are connected in parallel; a first end of the first jog switch S1 is connected to the backup power supply BAT, and a second end of the first jog switch S1 is connected to a drain of a P-channel field effect transistor; the drain of the P-channel field effect transistor Q1 is connected to a first end of a first current-limiting resistor R1; a second end of the first current-limiting resistor R1 is connected to an input end of the microcontroller 6 and a first end of a pull-down resistor R2, respectively; a second end of the pull-down resistor R2 is grounded GND;

[0026] a gate of the P-channel field effect transistor Q1 is connected to a first end of a second current-limiting resistor R3 and a collector of an NPN transistor Q2, respectively; a base of the NPN transistor Q2 is connected to a first end of a third current-limiting resistor R4; an emitter of the NPN transistor Q2 is grounded; a source of the P-channel field effect transistor Q1 is connected to the backup power supply BAT; a second end of the second current-limiting resistor R3 is connected to the backup power supply BAT; a second end of the third current-limiting resistor R4 is connected to an output end of the microcontroller 6;

[0027] the main power supply VCC is connected to an anode of a second Schottky diode D2, a cathode of the second Schottky diode D2 is connected to a cathode of a first Schottky diode D1 and a VDD pin of the microcontroller 6, respectively; an anode of the first Schottky diode D1 is connected to the first end of the first current-limiting resistor R1.

[0028] Wherein, a VSS pin of the microcontroller 6 is connected to the ground GND; the P-channel field effect transistor Q1 is a PMOS (P-channel Metal-Oxide-Semiconductor Field-Effect Transistor).

[0029] In actual application, in the non-working state of the sensor, that is, when the main power supply VCC is disconnected. Among them, if the sensor shell 1 is not damaged, the jog switches S1 and S2 are both in the disconnected state, and the backup power supply BAT cannot supply power to the microcontroller 6 through the first jog switch S1 or the second jog switch S2. At this time, the entire circuit has no power supply, and the microcontroller 6 does not work and is in standby state.

[0030] If the sensor housing 1 is broken, the first toggle switch S1 and / or the second toggle switch S2 is in the closed state, the backup power BAT supplies power to the microcontroller 6 through the first Schottky diode D1. At this time, the first Schottky diode D1 is turned on, the microcontroller 6 detects a high level and judges that the housing has been opened, and permanently saves its state.

[0031] It is worth noting that in the case of backup power damage, even if the housing is broken, the microcontroller 6 cannot obtain power supply, so it will not work, and it cannot detect the state of the housing being opened.

[0032] In actual application, in the working state of the sensor, that is, when the main power VCC is connected. The main power VCC supplies power to the microcontroller 6 through the second Schottky diode D2. The microcontroller 6 power-on initialization process is as follows: after the microcontroller MCU is powered on, in the case that the output end P41 is pulled low, at this time, the base of the transistor Q2 does not have enough current and is not turned on. Because Q2 is not turned on, the gate of Q1 is connected to BAT through resistor R3, and the gate voltage is high (close to BAT), so Q1 is not turned on, and the input end P42 detects a low level. Among them, in the case that the sensor housing 1 is not broken and the toggle switch 4 is in the off state, the microcontroller 6 input end P42 will detect a low level.

[0033] Among them, the microcontroller 6 can perform a preliminary detection on whether the backup power BAT is damaged, and the specific process includes: the microcontroller 6 pulls the output end P41 high, the transistor Q2 is turned on to make the gate voltage of the field effect transistor Q1 low, and the field effect transistor Q1 is turned on. At this time, the input end P42 of the microcontroller 6 is connected with the backup power BAT through the first current limiting resistor R1 and the field effect transistor Q1, if the microcontroller 6 input end P42 detects a high level, it proves that the sensor housing 1 is not broken; if a low level is detected, it proves that the backup power has been damaged, and the microcontroller 6 permanently saves its backup power damage state. After the above detection is completed, the microcontroller 6 pulls the output end P41 low to disconnect the transistor Q2 and the field effect transistor Q1, reducing the consumption of the backup power BAT.

[0034] After the preliminary detection is completed, the microcontroller 6 continuously scans the level of the input end P42, if the level of the input end P42 is high, the current state of the toggle switch 4 is closed, and it is determined that the sensor housing 1 is broken. If the level of the input end P42 is low, the output end P41 of the microcontroller 6 is pulled high, and the backup power is further judged by detecting the high and low levels of P42.

[0035] It is worth mentioning that the microcontroller 6 can detect whether the backup power supply is damaged, ensuring that the state of the damaged backup power supply can also be detected. The detected state of the damaged backup power supply is permanently saved, and can be reminded in real time or checked afterwards when the main power supply is working.

[0036] That is, when the main power supply VCC is not connected and the shell is not damaged, the jog switch 4 is in an open state, at which time the circuit has no power supply and does not work. If the backup power supply is damaged, the microcontroller 6 will also have no power supply and not work. If the sensor shell 1 is damaged, the jog switch 4 is in a closed state, at which time the backup power supply BAT supplies power to the microcontroller 6 through the first Schottky diode D1. The backup power supply BAT pulls the input end P42 of the microcontroller 6 to high level, and the microcontroller 6 detects the high level and permanently saves the state of the opening of the shell.

[0037] In some embodiments, the sensor comprises a digital load cell.

[0038] In some embodiments, the digital load cell comprises a sensor shell 1, an elastic body, and a strain gauge 3; the elastic body and the sensor shell form a deformation space therebetween; the strain gauge 3 is attached to the side surface of the elastic body; the strain gauge 3 comprises at least one; and the strain gauge 3 generates an electrical signal when the deformation body is deformed.

[0039] The deformation space is used to accommodate the volume change of the elastic body when the elastic body is deformed and to place the circuit and the wiring.

[0040] Specifically, the elastic body comprises a deformation body 7, a deformation body 8, and a support body 9. The support body 9, the deformation body 7, and the deformation body 8 are integrated. The sensor upper cover 10 is arranged on the support body 9. The sensor base 11 is in a U shape, and the deformation body 7 and the deformation body 8 are connected to the U-shaped side wall of the sensor base 11, respectively. The elastic body, the sensor upper cover 10, and the sensor base 11 are integrally formed and are made of the same metal material. The sensor upper cover 10 is connected to the scale table and is used to load the measured object.

[0041] In actual application, the measured object can be a car. When the scale table on the sensor upper cover 10 loads the car, the deformation body 7 and the deformation body 8 are slightly deformed, at which time the strain gauge 3 attached to the deformation body 7 and the deformation body 8 converts the slight deformation into an electrical signal.

[0042] The sensor shell forms a sealed structure between the sensor upper cover 10 and the sensor base 11.

[0043] For example, one strain gauge can be attached to the deformation body 7, and one strain gauge can be attached to the deformation body 8.

[0044] In some embodiments, the digital load cell further comprises a signal conditioning circuit and an analog-to-digital converter; the strain gauge 3 is connected to the signal conditioning circuit; the signal conditioning circuit is connected to the analog-to-digital converter; the analog-to-digital converter is connected to the microcontroller 6; the signal conditioning circuit U2 receives the electrical signal of the strain gauge 3 for amplification, filtering, compensation and linearization processing to output an analog signal; the analog-to-digital converter converts the analog signal into a digital signal and sends it to the microcontroller 6.

[0045] The signal conditioning circuit is an electronic circuit used to process and optimize the raw signals output by sensors. Its main purpose is to convert weak, nonlinear or noisy signals generated by sensors into standard signal forms suitable for subsequent processing, transmission or display. Signal conditioning circuits play a crucial role in various measurement systems, automation control systems, and communication systems, ensuring signal quality and reliability.

[0046] Referring to Figure 2 , the sensor housing 1 has a cavity 2, a digital module 5, a strain gauge 3, and a momentary switch 4 inside the cavity 2. The digital module 5 includes a microcontroller 6. The digital module 5 is arranged at the circular groove at the bottom of the support body 9.

[0047] In some embodiments, the microcontroller 6 further comprises a timer; the timer is provided with a preset interval time; the microcontroller 6 detects the level of the input end P42 of the microcontroller according to the preset interval time.

[0048] In actual application, the microcontroller 6 pulls up the output end P41 based on the timer, and judges whether the backup battery BAT is damaged by detecting the level of the input end P42.

[0049] In some embodiments, the sensor anti-opening device based on the momentary switch further comprises a display, which is connected to the microcontroller 6 through a communication interface.

[0050] Once the sensor housing 1 is opened or the backup battery BAT is damaged, the user can be reminded through the display alarm or Internet of Things push, etc.

[0051] The model of the microcontroller 6 includes but is not limited to any one of 51 single-chip microcomputers, arm cortex-m series microcontrollers, and RENESAS RL78 series microcontrollers.

[0052] The application uses the jog switch 4 as an electronic seal to ensure that the digital weighing sensor shell 1 is opened, and the case where the internal remote control device and other equipment are installed can be found in time. Power supply is carried out by using a backup power supply, which ensures that the opened state can be detected in the non-working state and the main power supply is not connected. The backup power supply consumes very little when the sensor shell 1 is not damaged, and only needs to supply power to the microcontroller 6 after the sensor is in a non-working state and the sensor shell 1 is damaged, which prolongs the service life of the backup power supply and ultimately improves the reliability and safety of the sensor.

[0053] The technical features of the above embodiments can be combined in any manner. In order to make the description simple, all possible combinations of the technical features in the above embodiments are not described, but as long as the combinations of the technical features do not contradict, they should be considered as the scope of the present application.

[0054] The principles and implementation modes of the present application are described by applying specific examples herein, and the above embodiment descriptions are only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In conclusion, the content of the present application should not be understood as a limitation.

Claims

1. A sensor anti-opening device based on a momentary switch, characterized in that, The sensor and a microcontroller, a backup power supply, a plurality of momentary switches and a detection circuit arranged inside the sensor; A plurality of the momentary switches are arranged inside the sensor housing; The plurality of the momentary switches are sealed in key positions inside the sensor housing; the key positions include all positions that need to be disassembled when the sensor housing is disassembled; The sealed momentary switches are in contact with the sensor housing, and the sensor housing applies pressure to the momentary switches; the current state of the momentary switches is an open state; The detection circuit is connected with the microcontroller, the backup power supply and the plurality of momentary switches respectively; the detection circuit includes a main power supply; The microcontroller is connected with the backup power supply through the plurality of momentary switches; The microcontroller determines whether the sensor housing is opened according to the current state of the plurality of momentary switches; the current state includes an open state and a closed state; The microcontroller determines whether the sensor housing is opened based on the backup power supply and any momentary switch in the closed state when the main power supply is not turned on; the microcontroller determines whether the sensor housing is opened based on the detection circuit when the main power supply is turned on. The detection circuit includes a P-channel field effect transistor, a first current limiting resistor, a pull-down resistor, a second current limiting resistor, a third current limiting resistor, an NPN transistor, a first Schottky diode and a second Schottky diode.

2. The point switch based sensor anti-opening device according to claim 1, characterized in that, 3. The momentary switch-based sensor anti-opening device according to claim 2, wherein The momentary switches include a first momentary switch and a second momentary switch; The first momentary switch and the second momentary switch are connected in parallel; The first end of the first momentary switch is connected with the backup power supply, and the second end of the first momentary switch is connected with the drain of the P-channel field effect transistor; the drain of the P-channel field effect transistor is connected with the first end of the first current limiting resistor; the second end of the first current limiting resistor is connected with the input of the microcontroller and the first end of the pull-down resistor respectively; the second end of the pull-down resistor is grounded; The gate of the P-channel field effect transistor is connected with the first end of the second current limiting resistor and the collector of the NPN transistor respectively; the base of the NPN transistor is connected with the first end of the third current limiting resistor; the emitter of the NPN transistor is grounded; the source of the P-channel field effect transistor is connected with the backup power supply through the second current limiting resistor; the second end of the second current limiting resistor is connected with the backup power supply; the second end of the third current limiting resistor is connected with the output of the microcontroller; The main power supply is connected with the anode of the second Schottky diode; the cathode of the second Schottky diode is connected with the cathode of the first Schottky diode and the VDD pin of the microcontroller respectively; the anode of the first Schottky diode is connected with the first end of the first current limiting resistor. The sensor includes a digital load cell.

4. The point switch based sensor anti-opening device according to claim 1, wherein, The digital load cell includes a sensor housing, an elastomer and a strain gauge; the strain gauge is attached to the elastomer.

5. The point switch based sensor anti-opening device according to claim 4, characterized in that, ​ 6. The point switch based sensor anti-opening device according to claim 5, wherein, The strain gauge comprises at least one; the strain gauge generates an electric signal when the elastomer is deformed.

7. The sensor anti-opening device based on the jog switch according to claim 5, characterized by, The digital weighing sensor further comprises a signal conditioning circuit and an analog-to-digital converter; The strain gauge is connected with the signal conditioning circuit; The signal conditioning circuit is connected with the analog-to-digital converter; The analog-to-digital converter is connected with the microcontroller; The signal conditioning circuit receives the electric signal of the strain gauge for amplification, filtering, compensation and linearization processing to output an analog signal; the analog-to-digital converter converts the analog signal into a digital signal and sends the digital signal to the microcontroller.

8. The point switch based sensor anti-opening device according to claim 1, wherein, The microcontroller further comprises a timer; the timer is provided with a preset interval time; the microcontroller detects the level of the input end of the microcontroller according to the preset interval time.

9. The point switch based sensor anti-opening device according to claim 1, wherein, The sensor anti-opening device based on the jog switch further comprises a display connected with the microcontroller through a communication interface.

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