Resistance type electronic water gauge

Abstract

The utility model relates to the technical field of liquid level detection devices, in particular to a resistance type electronic water gauge which comprises a water gauge shell and a control box arranged at the top of the water gauge shell, a resistance plate is connected to the bottom of the water gauge shell, and a plurality of contacts are arranged on the resistance plate; the resistance plate is fixed to the bottom of the water gauge shell through the insulating support, and the resistance plate and the insulating support are of an integrally-formed structure. The device is strong in structural rigidity and high in durability, can effectively prevent the resistance plate and the control module from being interfered or damaged by the outside, is low in maintenance cost, and can realize wireless interconnection control of an upper computer by being connected with a communication interface in a matched manner on the basis of resistance measurement; the control module issues an instruction to the resistance plate, the resistance plate performs detection according to the instruction, single-measuring-point measurement can be realized, all measuring points do not need to form a loop, and the power consumption is low.

Description

Technical Field

[0001] The present application belongs to the technical field of liquid level detection devices, and more specifically, to a resistive electronic water gauge. Background Art

[0002] Liquid level detection is an indispensable technology in industrial automation. Its purpose is to monitor the liquid in the container or pipeline in real time to ensure the safety and stability of the production process. At present, most traditional liquid level detection uses a measuring rod and a float to observe the liquid level. When observing with a float and a measuring rod, due to the friction between the measuring rod and the pipe wall, when the water level rises or falls, the measuring rod needs to overcome the friction between the pipe wall to move, which will cause the position of the float (i.e. the liquid level) to be inaccurate. In addition, the structure of the measuring rod and the float is relatively complex, easy to damage and clog, and the maintenance cost is high. Summary of the invention

[0003] To achieve the above object, the technical solution adopted in the present application is: to provide a resistive electronic water gauge, comprising a water gauge housing and a control box arranged on the top of the water gauge housing, the bottom of the water gauge housing is connected to a resistance plate, and the resistance plate is provided with a plurality of contacts;

[0004] The resistor plate is fixed to the bottom of the water gauge housing through an insulating bracket, and the resistor plate and the insulating bracket are an integrally formed structure.

[0005] Optionally, a plurality of contact mounting holes are provided on the resistor plate, and the contact mounting holes are used to mount contacts;

[0006] The contact is protruded from the contact installation hole, and the contact is sealed and connected to the contact protrusion hole.

[0007] Optionally, the water gauge housing is made of stainless steel.

[0008] Optionally, the control box comprises a box body and a top cover, and the top cover is detachably arranged on the box body;

[0009] A box body protrusion is arranged on the top of the box body; a first locking mechanism is arranged on the top cover, a box body locking mechanism is hinged on the first locking mechanism, and the box body locking mechanism can rotate around the first locking mechanism.

[0010] Optionally, a control module is provided in the control box, and the control module includes a main control unit, and the main control unit is respectively connected to a switching power supply regulator unit, a DAC conversion unit, an analog output unit, an RS485 interface unit and a terminal.

[0011] Optionally, the main control unit includes a chip U1, pins 13 to 16 of the chip U1 are connected to terminal U6, pins 29 to 31 of the chip U1 are connected to the RS485 interface unit, and pins 40 to 42 of the chip U1 are connected to the DAC conversion unit.

[0012] Optionally, the analog output unit includes an operational amplifier U10.1, an operational amplifier U10.2, and an operational amplifier U10.3. Pin 1 of the operational amplifier U10.1 is connected to pin 2 of the operational amplifier U10.1 via capacitor C16, and pin 1 of the operational amplifier U10.1 is connected to one pin of the transistor Q2 via resistor R19; pin 2 of the operational amplifier U10.1 is respectively connected to the other pin of the transistor Q2 and one end of the resistor R23 via resistor R24, and the other end of the resistor R23 is grounded; pin 3 of the operational amplifier U10.1 is grounded via resistor R21, and pin 3 of the operational amplifier U10.1 is also connected to the power supply VOUT; pin 4 of the operational amplifier U10.1 is connected to a 12V power supply, and the 12V power supply is connected to the power supply VCC via diode D9; pin 11 of the operational amplifier U10.1 is grounded;

[0013] The third pin of the transistor Q2 is connected to the power supply VCC via the resistor R15, the third pin of the transistor Q2 is also connected to the 5th pin of the operational amplifier U10.2, the 6th pin of the operational amplifier U10.2 is respectively connected to one end of the resistor R12 and one end of the capacitor C17, the other end of the resistor R12 is connected to the power supply VCC via the resistor R13, the other end of the resistor R12 is also connected to one pin of the temperature and humidity sensor Q1, the other end of the capacitor C17 is respectively connected to the 7th pin of the operational amplifier U10.2 and one end of the resistor R18, the other end of the resistor R18 is connected to the other pin of the temperature and humidity sensor Q1, and the third pin of the temperature and humidity sensor Q1 is connected to the power supply OUT via the diode D10 and the resistor R20 connected in series;

[0014] Pin 9 of the operational amplifier U10.3 is grounded via resistor R25, and pin 9 of the operational amplifier U10.3 is also connected to pin 8 of the operational amplifier U10.3 via resistor R22, and pin 8 of the operational amplifier U10.3 is grounded via diode U9, and pin 8 of the operational amplifier U10.3 is also connected to power supply OUT via series resistors R26 and R27, and pin 10 of the operational amplifier U10.3 is connected to power supply VOUT.

[0015] Optionally, the resistor board includes a chip U12 and a chip U13, and pins 1 and 2 of the chip U12 are respectively connected to pin 3 of the analog switch R12, pin 3 of the analog switch R20 and one end of the resistor R18 via the resistor R13, and pin 5 of the chip U12 is also connected to the other end of the resistor R18;

[0016] Pins 6 and 7 of chip U12 are also connected to one end of resistor R19 and one end of resistor R16 respectively through resistor R15. The other end of resistor R19 is grounded, and the other end of resistor R16 is connected to pin 4 of chip U13; pin 3 of chip U13 is connected to pin 4 of terminal H12 and pin 3 of terminal H13 respectively; pin 6 of chip U13 is connected to pin 5 of chip U11.

[0017] Optionally, the 15th pin of the chip U11 is connected to the 6th pin of the analog switch R12, the 1st pin of the chip U11 is connected to the 6th pin of the analog switch R20, the 2nd pin of the chip U11 is respectively connected to the 11th pin of the analog switch R12 and the 11th pin of the analog switch R20, the 3rd pin of the chip U11 is respectively connected to the 10th pin of the analog switch R12 and the 10th pin of the analog switch R20, the 4th pin of the chip U11 is respectively connected to the 9th pin of the analog switch R12 and the 9th pin of the analog switch R20, the 6th pin of the chip U13 is grounded via the resistor R11 and the diode LED11; the 9th pin of the chip U11 is connected to the 9th and 10th pins of the contact terminal H13, the 8th pin and the 13th pin of the chip U11 are both grounded, and the 10th pin and the 16th pin of the chip U11 are both connected Connected to the power supply VCC, the 10th and 16th pins of the chip U11 are also grounded after passing through the capacitor C11, the 11th pin of the chip U11 is connected to the 5th pin of the wiring terminal H13 and the 6th pin of the wiring terminal H12, the 6th pin of the wiring terminal H13 is connected to the 5th pin of the wiring terminal H12, the 12th pin of the chip U11 is connected to the 7th pin of the wiring terminal H13 and the 8th pin of the wiring terminal H12, the 8th pin of the wiring terminal H13 is connected to the 7th pin of the contact terminal H12, the 14th pin of the chip U11 is respectively connected to the 9th and 10th pins of the wiring terminal H12, the 1st and 2nd pins of the wiring terminal H13 are both connected to the power supply VCC, the 1st and 2nd pins of the wiring terminal H12 are both connected to the power supply VCC; the 15th pin of the chip U11 is connected to the 6th pin of the analog switch R12.

[0018] Optionally, pin 5 of the analog switch R12 is connected to pin 1 of the chip U15, pin 12 of the analog switch R12 is connected to pin 1 of the chip U23, pin 13 of the analog switch R12 is connected to pin 1 of the chip U21, pin 14 of the analog switch R12 is connected to pin 1 of the chip U19, and pin 15 of the analog switch R12 is connected to pin 1 of the chip U17;

[0019] Pin 5 of analog switch R20 is connected to pin 1 of chip U22, pin 12 of analog switch R20 is connected to pin 1 of chip U14, pin 13 of analog switch R20 is connected to pin 1 of chip U16, pin 14 of analog switch R20 is connected to pin 1 of chip U18, and pin 15 of analog switch R20 is connected to pin 1 of chip U20.

[0020] The resistive electronic water gauge of the present application has a simple and reasonable structure. It only requires a stainless steel water gauge shell and a control box for protecting the control circuit to be installed on the device to be tested, without the need for any moving parts or mechanical structures. The water gauge shell adopts a stainless steel anti-corrosion design to enhance structural rigidity and improve durability. It is reliable in operation, and the water gauge shell and the control box are waterproof and dustproof, which can effectively prevent the resistance plate and the control module from being interfered with or damaged by the outside world. The maintenance cost is low, and the durability and stability of the resistance plate and the control module do not need to be frequently replaced or repaired. It only needs to regularly check whether the voltage and current are normal. On the basis of resistance measurement, in conjunction with the connection communication interface, wireless interconnection control of the host computer can be realized. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0022] Figure 1 This is a schematic diagram of the structure of the resistive electronic water gauge of this application;

[0023] Figure 2 for Figure 1 Enlarged view of M in the middle;

[0024] Figure 3 This is a bottom view of the control box;

[0025] Figure 4 This is the front view of the resistive electronic water gauge of this application;

[0026] Figure 5 This is the main view of the control box;

[0027] Figure 6 This is the right side view of the control box;

[0028] Figure 7 This is the left view of the control box;

[0029] Figure 8 It is a structural schematic diagram of the resistor plate;

[0030] Fig. 9 for Figure 8 Enlarged view of N in the middle;

[0031] Fig.10 The circuit diagram of the main control unit;

[0032] Fig.11 is a circuit diagram of a power supply unit;

[0033] Fig.12 This is the circuit diagram of the analog output unit;

[0034] Fig.13 This is the circuit diagram of the RS485 interface unit;

[0035] Fig.14 is the circuit diagram of the terminal;

[0036] Fig.15 is a circuit diagram of a DAC conversion unit;

[0037] Fig.16 is a circuit diagram of a switching power supply regulator unit;

[0038] Fig.17 The circuit diagram of the resistor board.

[0039] Explanation of symbols in the figure:

[0040] 1-control box; 2-water gauge housing; 3-mounting bracket; 4-shell hole; 5-resistance plate; 51-contact mounting hole; 6-bolt fixing hole; 10-control box carrier board; 11-first locking mechanism; 12-elastic door closing device; 13-box body locking mechanism; 131-lock tongue; 132-unlocking force arm; 133-groove; 14-box body; 141-box body protrusion; 15-top cover; 16-second locking mechanism.

[0041] The control module includes a main control unit, a power supply unit, a switching power supply regulator unit, a DAC conversion unit, an analog output unit, an RS485 interface unit and a terminal. The power supply unit is connected to the main control unit, and the main control unit is respectively connected to the switching power supply regulator unit, the DAC conversion unit, the analog output unit, the RS485 interface unit and the terminal. DETAILED DESCRIPTION

[0042] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0043] A resistive electronic water gauge provided in an embodiment of the present application is now described. Figure 1 and Figure 2 A resistive electronic water gauge comprises a water gauge housing 2 and a control box 1 disposed on the top of the water gauge housing 2. Preferably, the control box 1 is connected to the top of the water gauge housing 2 by welding.

[0044] The material of the water gauge housing 2 is stainless steel, which has waterproof function. Of course, the water gauge housing 2 can also be made of other corrosion-resistant materials.

[0045] The control box 1 is fixed on the control box carrier 10, and the water gauge housing 2 and the control box carrier 10 are connected by laser welding to achieve the connection between the water gauge housing 2 and the control box carrier 10. The water gauge housing 2 is a sealed cylindrical structure.

[0046] See also Figure 8 and Fig. 9 The bottom of the water gauge housing 2 is connected with a resistor plate 5, and a plurality of contacts are arranged on the resistor plate 5. Specifically, the resistor plate 5 is fixed to the bottom of the water gauge housing 2 through an insulating bracket, and a plurality of contact mounting holes 51 are arranged on the resistor plate 5. The contact mounting holes 51 are used to mount contacts for measurement, and the contacts are arranged protruding from the contact mounting holes 51, and the contacts and the contact mounting holes 51 are sealed.

[0047] Preferably, the resistor plate 5 and the insulating support are an integrally formed structure. The insulating support is a carrier, and the resistor plate 5 is arranged at the lower part of the insulating support.

[0048] Shell holes 4 are provided on both sides of the water gauge housing 2 , and the resistor plate 5 and the insulating bracket are fixed to the water gauge housing 2 through the cooperation between the shell holes 4 and the bolts.

[0049] The bottom of the water gauge housing 2 is provided with a bolt fixing hole 6, and the bolt fixing hole 6 cooperates with the bolt to realize the connection between the water gauge housing 2 and the resistor plate 5 and the insulating bracket.

[0050] A control module is arranged in the control box 1, and the control module applies a constant voltage to the resistor plate 5 and generates currents of different magnitudes according to different liquid levels. By arranging the control box 1 on the top of the water gauge housing 2, the control module in the control box 1 can be better protected from external interference.

[0051] See also Figure 1 and Figure 2 , a mounting bracket 3 can be provided at the bottom of the water gauge housing 2, and the mounting bracket 3 is used to fix the water gauge housing 2 in the device to be tested. For example, the water gauge housing 2 can be fixed in the tank to be tested or on the wall at the bottom of the bridge through the mounting bracket 3. Multiple groups of mounting brackets 3 can be provided, and two adjacent groups are arranged at the bottom of the water gauge housing 2 with equal spacing and / or unequal spacing, and each group includes two mounting brackets 3 and are mirror-imaged and arranged on both sides of the water gauge housing 2.

[0052] See also Figures 1 to 3 The control box 1 is fixed on the control box carrier 10. The control box 1 includes a box body 14 and a top cover 15, and the top cover 15 is detachably arranged on the box body 14.

[0053] For details, see Figure 3 , Figures 4 to 7The top of the box body 14 is provided with a box body protrusion 141; the top cover 15 is provided with a first locking mechanism 11, and the first locking mechanism 11 is hinged with a box body locking mechanism 13, and the box body locking mechanism 13 can rotate around the first locking mechanism 11. The box body locking mechanism 13 includes an unlocking force arm 132 and a locking tongue 131;

[0054] The first locking mechanism 11 is further provided with a groove 133 , which is engaged with the protrusion 141 of the box body and the top cover 15 is installed on the box body 14 through the cooperation of the locking tongue 131 .

[0055] The first locking mechanism 11 is arranged on one side of the box body 14 and a plurality of first locking mechanisms 11 can be arranged. The other side of the box body 14 is provided with a second locking mechanism 16, and an elastic door closing device 12 is hinged on the second locking mechanism 16, and the elastic door closing device 12 can be opened and closed and buckled on the box body protrusion 141.

[0056] When there is liquid in the device to be tested (such as a tank), the liquid submerges the water gauge housing 2, and then contacts the corresponding contacts on the resistor plate 5, forming a loop. After the control module applies a constant voltage to the resistor plate 5, a current proportional to the liquid level is generated in the loop. The control module outputs the water level height by calculating and analyzing the current, and sends it to the host computer or display screen through the data output interface.

[0057] See also Figures 10 to 16 The control module includes a main control unit, a power supply unit, a switching power supply regulator unit, a DAC conversion unit, an analog output unit, an RS485 interface unit and a terminal. The power supply unit is connected to the main control unit, and the main control unit is respectively connected to the switching power supply regulator unit, the DAC conversion unit, the analog output unit, the RS485 interface unit and the terminal.

[0058] Specifically, the main control unit includes a chip U1, which is obtained from the market and has a model number of GD32F103C8T6. Pins 1, 9, 24, 36, and 48 of the chip U1 are all connected to a 3.3V power supply, which is connected to ground via a resistor R16 and a diode LED1 connected in series, and connected to pin 7 of the chip U1 via a resistor R14; the 3.3V power supply is connected to ground via a resistor R14 and then a capacitor C18; the 3.3V power supply is connected to ground via capacitors C19, C20, C21, C22, and C23 connected in parallel; the 3.3V power supply is also connected to pin 1 of the wiring terminal H1, pin 2 of the wiring terminal H1 is connected to pin 37 of the chip U1, pin 3 of the wiring terminal H1 is connected to pin 34 of the chip U1, and pin 4 of the wiring terminal H1 is grounded. The model number of the wiring terminal H1 is PZ254V-11-04P.

[0059] Pins 8, 23, 35 and 47 of chip U1 are all grounded.

[0060] Pin 7 of the chip U1 is connected to a reset circuit, which can be realized by using existing technology, so it will not be described in detail.

[0061] Pins 13 to 16 of chip U1 are connected to terminal U6, and the model of terminal U6 is PZ2.54-2*7.

[0062] Pin 1 and pin 2 of terminal U6 are connected to a 5V power supply, pin 3 and pin 4 of terminal U6 are connected to pin 13 of chip U1, pin 5 and pin 6 of terminal U6 are connected to pin 14 of chip U1, pin 7 and pin 8 of terminal U6 are connected to pin 15 of chip U1, pin 9 and pin 10 of terminal U6 are connected to pin 16 of chip U1, and pin 13 and pin 14 of terminal U6 are grounded.

[0063] Pins 29 to 31 of the chip U1 are connected to the RS485 interface unit. The RS485 interface unit includes a chip U3. The model of the chip U3 is TP8RS485E-SR.

[0064] Pin 1 of chip U3 is connected to pin 31 of chip U1, pins 2 and 3 of chip U3 are connected to pin 29 of chip U1, pin 4 of chip U3 is connected to pin 30 of chip U1, pin 5 of chip U3 is grounded, pin 6 of chip U3 is connected to one end of resistor R8, the other end of resistor R8 is connected to a 3.3V power supply via resistor R9, the other end of resistor R8 is also grounded via diode D8, and the other end of resistor R8 is also connected to the RS485A interface via fuse F3; pin 7 of chip U3 is connected to one end of resistor R5, the other end of resistor R5 is grounded via resistor R4, the other end of resistor R5 is grounded via diode D2, and the other end of resistor R5 is also connected to the RS485B interface via fuse F2; pin 8 of chip U3 is connected to a 3.3V power supply, and pin 8 of chip U3 is also grounded via capacitor C5.

[0065] Pins 40 to 42 of the chip U1 are connected to a DAC conversion unit. The DAC conversion unit includes a chip U4. The model of the chip U4 is DAC7512N / 250G4.

[0066] Pin 1 of chip U4 is connected to the power supply VOUT, pin 2 of chip U4 is grounded, pin 3 of chip U4 is connected to the 3.3V power supply, and pin 3 of chip U4 is also grounded after capacitor C12, pin 4 of chip U4 is connected to pin 42 of chip U1, pin 5 of chip U4 is connected to pin 41 of chip U1, and pin 6 of chip U4 is connected to pin 40 of chip U1.

[0067] Pin 44 of chip U1 is grounded via resistor R11.

[0068] The analog output unit includes operational amplifier U10.1, operational amplifier U10.2, and operational amplifier U10.3. The models of operational amplifier U10.1, operational amplifier U10.2, and operational amplifier U10.3 are all TLV2374IPWRG4.

[0069] Pin 1 of the operational amplifier U10.1 is connected to pin 2 of the operational amplifier U10.1 via capacitor C16, and pin 1 of the operational amplifier U10.1 is connected to one pin of the transistor Q2 via resistor R19; pin 2 of the operational amplifier U10.1 is respectively connected to the other pin of the transistor Q2 and one end of the resistor R23 via resistor R24, and the other end of the resistor R23 is grounded; pin 3 of the operational amplifier U10.1 is grounded via resistor R21, and pin 3 of the operational amplifier U10.1 is also connected to the power supply VOUT; pin 4 of the operational amplifier U10.1 is connected to a 12V power supply, and the 12V power supply is connected to the power supply VCC via diode D9; pin 11 of the operational amplifier U10.1 is grounded.

[0070] The third pin of the transistor Q2 is connected to the power supply VCC via the resistor R15, and the third pin of the transistor Q2 is also connected to the 5th pin of the operational amplifier U10.2. The 6th pin of the operational amplifier U10.2 is respectively connected to one end of the resistor R12 and one end of the capacitor C17. The other end of the resistor R12 is connected to the power supply VCC via the resistor R13. The other end of the resistor R12 is also connected to one pin of the temperature and humidity sensor Q1. The other end of the capacitor C17 is respectively connected to the 7th pin of the operational amplifier U10.2 and one end of the resistor R18. The other end of the resistor R18 is connected to the other pin of the temperature and humidity sensor Q1. The third pin of the temperature and humidity sensor Q1 is connected to the power supply OUT via the series-connected diode D10 and resistor R20.

[0071] Pin 9 of the operational amplifier U10.3 is grounded via resistor R25, and pin 9 of the operational amplifier U10.3 is also connected to pin 8 of the operational amplifier U10.3 via resistor R22, and pin 8 of the operational amplifier U10.3 is grounded via diode U9, and pin 8 of the operational amplifier U10.3 is also connected to power supply OUT via series resistors R26 and R27, and pin 10 of the operational amplifier U10.3 is connected to power supply VOUT.

[0072] The power supply unit includes chip U5 and chip U7. The model of chip U5 is TPMP2359DJ, and the model of chip U7 is TP2019-3.3YN5.

[0073] Pin 1 of chip U5 is connected to pin 6 of chip U5, one end of inductor L4, and one end of diode D7 respectively through capacitor C8, the other end of inductor L4 is connected to one end of resistor R7, the other end of resistor R7 is connected to one end of resistor R10 and pin 3 of chip U5 respectively, and the other end of resistor R10 is grounded; the other end of inductor L4 is also grounded through capacitor C9, capacitor C10 and capacitor C11 connected in parallel, and the other end of inductor L4 is also connected to a 5V power supply; pin 4 of chip U5 is connected to pin 5 of chip U5 through resistor R6, pin 5 of chip U5 is grounded through diode D6, capacitor C7, capacitor C6, and diode D5 connected in parallel, a diode D3 is also arranged between capacitor C6 and diode D5, diode D5 is connected to filter L3 in parallel, filter L3 is also connected to diode D4 in parallel, one end of diode D4 is connected to power terminal VIN through inductor L2 and fuse F1 connected in series, and power terminal VIN is also grounded through varistor RV1; the other end of diode D4 is grounded.

[0074] Pin 1 of chip U7 is connected to a 5V power supply, and pin 1 of chip U7 is also grounded via capacitor C13. Pin 1 of chip U7 is also connected to pin 3 of chip U7, and pin 2 of chip U7 is connected to capacitor C13. Pin 4 of chip U7 is grounded via capacitor C15, and pin 5 of chip U7 is connected to a 3.3V power supply, and pin 5 of chip U7 is grounded via capacitor C14.

[0075] The switching power supply regulator unit includes a chip U2, and the model of the chip U2 is TPMP2359DJ.

[0076] Pin 1 of chip 2 is connected to one end of inductor L1 via capacitor C1, one end of inductor L1 is connected to ground via diode D1, and one end of inductor L4 is connected to pin 6 of chip U2; pin 2 of chip U2 is grounded; pin 3 of chip U2 is grounded via resistor R3, pin 3 of chip U2 is connected to the other end of inductor L1 via resistor R2, the other end of inductor L1 is connected to capacitor C2, capacitor C3, and capacitor C4 in parallel and then grounded, and the other end of inductor L1 is connected to a 12V power supply; pin 4 of chip U2 is connected to pin 5 of chip U2 via resistor R1.

[0077] In the present application, the resistor board 5 is directly controlled by the single-chip microcomputer io, and the io uses the chip U11 (the chip U11 is an expansion chip), which can not only meet the needs of a large number of expansions, but also save a lot of io resources.

[0078] See also Fig.17 The resistor board 5 includes a chip U12 and a chip U13, both of which are commercially available. The model of the chip U12 is LMV358, and the model of the chip U13 is SN74LVC1G3157DCKR.

[0079] Pin 1 and Pin 2 of chip U12 are connected to Pin 3 of analog switch R12, Pin 3 of analog switch R20 and one end of resistor R18 respectively via resistor R13, Pin 3 of chip U12 is connected to power supply VCC via resistor R14, and Pin 3 of chip U12 is also connected to ground via resistor R17; Pin 4 of chip U12 is grounded, Pin 5 of chip U12 is grounded via capacitor C16, and Pin 5 of chip U12 is also connected to the other end of resistor R18;

[0080] Pin 8 of chip U12 is connected to the power supply VCC, and pin 8 of chip U12 is also grounded via capacitor C13.

[0081] Pins 6 and 7 of chip U12 are grounded via capacitor C15, and are also connected to one end of resistor R19 and one end of resistor R16 respectively via resistor R15. The other end of resistor R19 is grounded, and the other end of resistor R16 is connected to pin 4 of chip U13; pin 2 of chip U13 is grounded, and pin 3 of chip U13 is respectively connected to pin 4 of terminal H12 and pin 3 of terminal H13; pin 6 of chip U13 is connected to pin 5 of chip U11, and pin 5 of chip U13 is connected to power supply VCC, and pin 5 of chip U13 is also grounded via capacitor C17.

[0082] The chip U11 is obtained from the market, and its model is 74HC595D. Pin 15 of the chip U11 is connected to pin 6 of the analog switch R12, pin 1 of the chip U11 is connected to pin 6 of the analog switch R20, pin 2 of the chip U11 is connected to pin 11 of the analog switch R12 and pin 11 of the analog switch R20 respectively, pin 3 of the chip U11 is connected to pin 10 of the analog switch R12 and pin 10 of the analog switch R20 respectively, pin 4 of the chip U11 is connected to pin 9 of the analog switch R12 and pin 9 of the analog switch R20 respectively, pin 6 of the chip U13 is grounded via resistor R11 and diode LED11; pin 9 of the chip U11 is connected to pins 9 and 10 of the contact terminal H13, pins 8 and 13 of the chip U11 are both grounded, and the chip U1 Pin 10 and pin 16 of chip U11 are connected to power supply VCC, pin 10 and pin 16 of chip U11 are also grounded after capacitor C11, pin 11 of chip U11 is connected to pin 5 of wiring terminal H13 and pin 6 of wiring terminal H12, pin 6 of wiring terminal H13 is connected to pin 5 of wiring terminal H12, pin 12 of chip U11 is connected to pin 7 of wiring terminal H13 and pin 8 of wiring terminal H12, pin 8 of wiring terminal H13 is connected to pin 7 of contact terminal H12, pin 14 of chip U11 is respectively connected to pin 9 and pin 10 of wiring terminal H12, pin 1 and pin 2 of wiring terminal H13 are connected to power supply VCC, pin 1 and pin 2 of wiring terminal H12 are connected to power supply VCC; pin 15 of chip U11 is connected to pin 6 of analog switch R12.

[0083] Pin 7 and pin 8 of analog switch R12 are both grounded, pin 5 of analog switch R12 is connected to pin 1 of chip U15, pin 12 of analog switch R12 is connected to pin 1 of chip U23, pin 13 of analog switch R12 is connected to pin 1 of chip U21, pin 14 of analog switch R12 is connected to pin 1 of chip U19, pin 15 of analog switch R12 is connected to pin 1 of chip U17, pin 16 of analog switch R12 is connected to power supply VCC, and pin 16 of analog switch R12 is also grounded after capacitor C12.

[0084] Pins 7 and 8 of analog switch R20 are both grounded, pin 5 of analog switch R20 is connected to pin 1 of chip U22, pin 12 of analog switch R20 is connected to pin 1 of chip U14, pin 13 of analog switch R20 is connected to pin 1 of chip U16, pin 14 of analog switch R20 is connected to pin 1 of chip U18, pin 15 of analog switch R20 is connected to pin 1 of chip U20, pin 16 of analog switch R20 is connected to power supply VCC, and pin 16 of analog switch R20 is also grounded after capacitor C14.

[0085] It also includes a connection terminal H11 and a connection terminal H14.

[0086] Pin 1 of the wiring terminal H11 is connected to pin 1 of the wiring terminal H14, and pin 2 of the wiring terminal H11 is connected to pin 2 of the wiring terminal H14.

[0087] The resistive electronic water gauge of the present application has a simple and reasonable structure. It only requires a stainless steel water gauge shell and a control box for protecting the control circuit to be installed on the device to be tested, without the need for any moving parts or mechanical structures. The water gauge shell adopts a stainless steel anti-corrosion design to enhance the structural rigidity and improve durability. It is reliable in operation, and the water gauge shell and the control box are waterproof and dustproof, which can effectively prevent the resistance plate and the control module from being interfered with or damaged by the outside world. The maintenance cost is low, and the durability and stability of the resistance plate and the control module do not need to be frequently replaced or repaired. It is only necessary to regularly check whether the voltage and current are normal. On the basis of resistance measurement, in conjunction with the connection communication interface, wireless interconnection control of the upper computer can be realized. The control module sends instructions to the resistance plate, and the resistance plate performs detection according to the instructions, so that single measuring point measurement can be realized, without the need to form a loop for all measuring points, and the power consumption is low.

[0088] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A resistive electronic water gauge, comprising a water gauge housing and a control box arranged on the top of the water gauge housing, characterized in that: The bottom of the water gauge housing is connected with a resistor plate, and a plurality of contacts are arranged on the resistor plate; The resistor plate is fixed to the bottom of the water gauge housing through an insulating bracket, and the resistor plate and the insulating bracket are an integrally formed structure.

2. A resistive electronic water gauge as claimed in claim 1, characterized in that: The resistor plate is provided with a plurality of contact mounting holes, and the contact mounting holes are used for mounting contacts; The contact is protruded from the contact installation hole, and the contact is sealed and connected to the contact protrusion hole.

3. A resistive electronic water gauge as claimed in claim 1, characterized in that: The material of the water gauge housing is stainless steel.

4. A resistive electronic water gauge as claimed in claim 1, characterized in that: The control box comprises a box body and a top cover, and the top cover is detachably arranged on the box body; A box body protrusion is arranged on the top of the box body; a first locking mechanism is arranged on the top cover, a box body locking mechanism is hinged on the first locking mechanism, and the box body locking mechanism can rotate around the first locking mechanism.

5. A resistive electronic water gauge as claimed in claim 1, characterized in that: A control module is arranged in the control box, and the control module comprises a main control unit, and the main control unit is respectively connected with a switching power supply regulator unit, a DAC conversion unit, an analog output unit, an RS485 interface unit and a terminal.

6. A resistive electronic water gauge as claimed in claim 5, characterized in that: The main control unit includes a chip U1, pins 13 to 16 of the chip U1 are connected to the terminal U6, pins 29 to 31 of the chip U1 are connected to the RS485 interface unit, and pins 40 to 42 of the chip U1 are connected to the DAC conversion unit.

7. A resistive electronic water gauge as claimed in claim 4, characterized in that: The analog output unit includes an operational amplifier U10.1, an operational amplifier U10.2, and an operational amplifier U10.

3. Pin 1 of the operational amplifier U10.1 is connected to pin 2 of the operational amplifier U10.1 via capacitor C16, and pin 1 of the operational amplifier U10.1 is connected to one pin of the transistor Q2 via resistor R19; pin 2 of the operational amplifier U10.1 is respectively connected to the other pin of the transistor Q2 and one end of the resistor R23 via resistor R24, and the other end of the resistor R23 is grounded; pin 3 of the operational amplifier U10.1 is grounded via resistor R21, and pin 3 of the operational amplifier U10.1 is also connected to the power supply VOUT; pin 4 of the operational amplifier U10.1 is connected to a 12V power supply, and the 12V power supply is connected to the power supply VCC via diode D9; pin 11 of the operational amplifier U10.1 is grounded; The third pin of the transistor Q2 is connected to the power supply VCC via the resistor R15, the third pin of the transistor Q2 is also connected to the 5th pin of the operational amplifier U10.2, the 6th pin of the operational amplifier U10.2 is respectively connected to one end of the resistor R12 and one end of the capacitor C17, the other end of the resistor R12 is connected to the power supply VCC via the resistor R13, the other end of the resistor R12 is also connected to one pin of the temperature and humidity sensor Q1, the other end of the capacitor C17 is respectively connected to the 7th pin of the operational amplifier U10.2 and one end of the resistor R18, the other end of the resistor R18 is connected to the other pin of the temperature and humidity sensor Q1, and the third pin of the temperature and humidity sensor Q1 is connected to the power supply OUT via the diode D10 and the resistor R20 connected in series; Pin 9 of the operational amplifier U10.3 is grounded via resistor R25, and pin 9 of the operational amplifier U10.3 is also connected to pin 8 of the operational amplifier U10.3 via resistor R22, and pin 8 of the operational amplifier U10.3 is grounded via diode U9, and pin 8 of the operational amplifier U10.3 is also connected to power supply OUT via series resistors R26 and R27, and pin 10 of the operational amplifier U10.3 is connected to power supply VOUT.

8. A resistive electronic water gauge as claimed in claim 1, characterized in that: The resistor board includes a chip U12 and a chip U13, wherein the pin 1 and pin 2 of the chip U12 are respectively connected to the pin 3 of the analog switch R12, the pin 3 of the analog switch R20 and one end of the resistor R18 via the resistor R13, and the pin 5 of the chip U12 is also connected to the other end of the resistor R18; Pin 6 and pin 7 of chip U12 are connected to one end of resistor R19 and one end of resistor R16 respectively through resistor R15, the other end of resistor R19 is grounded, and the other end of resistor R16 is connected to pin 4 of chip U13; Pin 3 of chip U13 is connected to pin 4 of connection terminal H12 and pin 3 of connection terminal H13 respectively; pin 6 of chip U13 is connected to pin 5 of chip U11.

9. A resistive electronic water gauge as claimed in claim 8, characterized in that: Pin 15 of chip U11 is connected to pin 6 of analog switch R12, pin 1 of chip U11 is connected to pin 6 of analog switch R20, pin 2 of chip U11 is connected to pin 11 of analog switch R12 and pin 11 of analog switch R20 respectively, pin 3 of chip U11 is connected to pin 10 of analog switch R12 and pin 10 of analog switch R20 respectively, pin 4 of chip U11 is connected to pin 9 of analog switch R12 and pin 9 of analog switch R20 respectively, and pin 6 of chip U13 is grounded via resistor R11 and diode LED11; Pin 9 of chip U11 is connected to pin 9 and pin 10 of contact terminal H13, pin 8 and pin 13 of chip U11 are both grounded, pin 10 and pin 16 of chip U11 are both connected to power supply VCC, pin 10 and pin 16 of chip U11 are also grounded after capacitor C11, pin 11 of chip U11 is connected to pin 5 of wiring terminal H13 and pin 6 of wiring terminal H12, pin 6 of wiring terminal H13 is connected to pin 5 of wiring terminal H12, pin 12 of chip U11 is connected to pin 7 of wiring terminal H13 and pin 8 of wiring terminal H12, pin 8 of wiring terminal H13 is connected to pin 7 of contact terminal H12, pin 14 of chip U11 is respectively connected to pin 9 and pin 10 of wiring terminal H12, pin 1 and pin 2 of wiring terminal H13 are both connected to power supply VCC, pin 1 and pin 2 of wiring terminal H12 are both connected to power supply VCC; pin 15 of chip U11 is connected to pin 6 of analog switch R12.

10. A resistive electronic water gauge as claimed in claim 8, characterized in that: Pin 5 of analog switch R12 is connected to pin 1 of chip U15, pin 12 of analog switch R12 is connected to pin 1 of chip U23, pin 13 of analog switch R12 is connected to pin 1 of chip U21, pin 14 of analog switch R12 is connected to pin 1 of chip U19, and pin 15 of analog switch R12 is connected to pin 1 of chip U17; Pin 5 of analog switch R20 is connected to pin 1 of chip U22, pin 12 of analog switch R20 is connected to pin 1 of chip U14, pin 13 of analog switch R20 is connected to pin 1 of chip U16, pin 14 of analog switch R20 is connected to pin 1 of chip U18, and pin 15 of analog switch R20 is connected to pin 1 of chip U20.

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