Portable alternating-current and direct-current dual-purpose grounding resistance tester

Abstract

A portable AC-DC dual-purpose grounding resistance tester disclosed by the present invention comprises a box body, one side of the box body is fixedly provided with a heat dissipation fan, the other side of the box body is provided with a ventilation hole in a penetrating manner, one side of the heat dissipation fan is fixedly provided with a direction adjusting box, and the inner bottom of the direction adjusting box is slidably connected with a stirring frame. And a special-shaped disc is arranged above the shifting frame. A bidirectional motor is started, the output end of the bidirectional motor drives a cooling fan and a worm to rotate, the output end of a special-shaped disc drives a stirring frame to slide in a direction adjusting box, the stirring frame enables a stirring rod to swing along a limiting rod, an L-shaped sliding rod slides in the inner wall of the direction adjusting box, and during sliding, a stirring block pulls the L-shaped sliding rod to rotate in the direction adjusting box; and the flowing direction of heat dissipation air of the heat dissipation fan is changed, so that no-dead-corner cooling of electronic elements on the resistance tester body is realized, and the service life of the electronic elements is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of testing instruments, in particular to a portable AC / DC dual-purpose grounding resistance tester. Background Art

[0002] The AC / DC dual-purpose ground resistance tester is a resistance tester that can be used for both AC and DC, and has the advantages of high precision, good linearity and strong anti-interference ability. It can measure the ground resistance of various devices in the power, post and telecommunications, railways, petroleum, chemical industry, communications, mining and other departments, as well as the resistance value of low-resistance conductors. However, when used in some special places, the resistance tester is designed to be easy to carry.

[0003] In the prior art, for example, Chinese patent CN215415619U discloses a ground resistance tester, which includes a protective box, in which a tester body is installed, a grounding wire is installed at the bottom of the tester body, a connecting tube is installed at the bottom of the protective box, a connecting column is threadedly connected to the inner wall of the connecting tube, a grounding plate is installed at the bottom of the connecting column, and an end of the grounding wire away from the tester body is electrically connected to the connecting column.

[0004] At present, during the operation of most resistance testers, the working components in the test box will generate heat, causing the temperature in the test box to be too high, which will reduce the service life of the electronic components in the resistance tester, making it inconvenient to use. Summary of the invention

[0005] The purpose of the present invention is to provide a portable AC / DC dual-purpose ground resistance tester to solve the problems raised in the above background technology.

[0006] To achieve the above object, the present invention provides the following technical solutions: A portable AC / DC dual-purpose grounding resistance tester comprises a box body, a cooling fan is fixedly installed on one side of the box body, a ventilation hole is penetrated through the other side of the box body, a direction adjustment box is fixedly installed on one side of the cooling fan, a toggle frame is slidably connected to the inner bottom of the direction adjustment box, a special-shaped disk is arranged above the toggle frame, an output end of the special-shaped disk is slidably connected to the inner wall of the toggle frame, one end of the toggle frame is rotatably connected to a toggle rod, the middle part of the toggle rod is slidably connected to a limiting rod, one end of the limiting rod is fixedly connected to one side of the inner wall of the direction adjustment box, an L-shaped sliding rod is slidably connected to one side of the toggle rod, a plurality of reversing blades are rotatably connected to one side of the inner wall of the direction adjustment box and near the edge, a plurality of reversing blades are fixedly connected to a toggle block at one side edge of each of the reversing blades, and one side of each of the plurality of reversing blocks is rotatably connected to the upper end of the L-shaped sliding rod.

[0007] As a further preferred embodiment of the portable AC / DC ground resistance tester of the present invention, a bidirectional motor is fixedly installed on the input end of the cooling fan, and a worm is transmission-connected to the output end of the bidirectional motor, a turbine is meshed on one side of the worm, a transmission shaft is fixedly connected to the lower end of the turbine, and one end of the transmission shaft is fixedly connected to the middle part of the upper end of the special-shaped disk.

[0008] As a further preferred embodiment of the portable AC / DC ground resistance tester of the present invention, a second mounting frame is fixedly connected to the other side of the cooling fan, and a filter is slidably connected to the inner wall of the second mounting frame.

[0009] As a further preferred embodiment of the portable AC / DC dual-purpose ground resistance tester of the present invention, a disassembly cylinder is fixedly connected to one side of the mounting frame 2, an insertion rod is slidably connected to the inner wall of the disassembly cylinder, a reset spring is sleeved on one side of the outer wall of the insertion rod, one end of the reset spring is fixedly connected to one side of the inner wall of the disassembly cylinder, one end of the insertion rod is rotatably connected to a rotating handle, and one side of the outer wall of the rotating handle is rotatably connected to one side of the outer wall of the disassembly cylinder.

[0010] As a further preferred embodiment of the portable AC / DC dual-purpose ground resistance tester of the present invention, a resistance tester body is fixedly installed on the inner wall of the box, and the resistance tester body includes a voltage sampling circuit, a signal preprocessing circuit, a processor module, a display module, an interface module, a reset module and a power supply module; the voltage sampling circuit is connected to the processor module through the signal preprocessing circuit, and the display module, interface module, reset module and power supply module are respectively connected to the processor module.

[0011] As a further preferred embodiment of a portable AC / DC ground resistance tester of the present invention, the signal preprocessing circuit includes a voltage signal conditioning circuit, an analog switch unit, a voltage divider follower filter unit, and an A / D conversion unit. The voltage sampling circuit is connected to a controller module through the voltage signal conditioning circuit, the analog switch unit, the voltage divider follower filter unit, and the A / D conversion unit in sequence.

[0012] As a further preferred embodiment of a portable AC / DC ground resistance tester of the present invention, the voltage signal conditioning circuit includes a voltage signal input terminal, a resistor R3, a resistor R4, a resistor R5, a capacitor C2, and an operational amplifier U2. The voltage signal input terminal is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to one end of the resistor R4 and one end of the resistor R5, the other end of the resistor R5 is connected to one end of the capacitor C2, the other end of the capacitor C2 is respectively connected to the other end of the resistor R4 and the positive input terminal of the operational amplifier U1, and the negative input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2.

[0013] As a further preferred embodiment of a portable AC / DC ground resistance tester of the present invention, the voltage divider follower filter unit comprises an operational amplifier U3, a resistor R11, a resistor R12, an operational amplifier U4, a resistor R13, and a capacitor C7. The output end of the operational amplifier U3 is connected to one end of the resistor R12, and the other end of the resistor R12 is respectively connected to one end of the resistor R11 and the positive input end of the operational amplifier U4. The output end of the operational amplifier U4 is connected to one end of the resistor R13, and the other end of the resistor R13 is respectively connected to one end of the capacitor C7 and the A / D conversion unit. The other end of the capacitor C7 is grounded, and the other end of the resistor R11 is connected to the current signal conditioning circuit.

[0014] As a further preferred embodiment of the portable AC / DC dual-purpose ground resistance tester of the present invention, a protective cover is rotatably connected to one side of the box body near the edge, a fixed block is fixedly connected to one side of the protective cover, and a buckle is fixedly connected to the other side of the box body near the edge, and a buckle ring of the buckle is clamped to the outer wall of the fixed block.

[0015] As a further preferred embodiment of the portable AC / DC dual-purpose ground resistance tester of the present invention, a mounting frame 1 is fixedly connected to the middle of the other side of the box, and a carrying handle is rotatably connected to the inner wall of the mounting frame 1.

[0016] The present invention provides a portable AC / DC dual-purpose ground resistance tester, which has the following beneficial effects: 1. The present invention starts a bidirectional motor, and the output end of the bidirectional motor drives the cooling fan and the worm to rotate respectively, so that the output end of the special-shaped disk drives the toggle frame to slide in the adjustment box, and the toggle frame swings the toggle rod along the limit rod, and the L-shaped sliding rod slides in the inner wall of the adjustment box. When sliding, the toggle block pulls the L-shaped sliding rod to rotate in the adjustment box, changing the flow direction of the cooling air of the cooling fan, realizing the cooling of the electronic components on the resistance tester body without dead angles, and improving the service life of the electronic components.

[0017] 2. The present invention can remove the restriction of the filter by turning the handle, and then the filter can be pulled out from the second mounting frame, so as to realize the cleaning and replacement of the filter and prevent the filter holes in the filter from becoming smaller due to long-term use, thereby affecting the heat dissipation effect. 3. The signal to be collected in the present invention is processed successively through signal conditioning, analog switch, voltage follower and anti-aliasing filtering, and the link establishment time is analyzed, and then converted using a successive approximation AD chip. The collected signal has higher accuracy and is more stable and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention; Figure 2It is a schematic diagram of the cross-sectional structure of the box body in the present invention; Figure 3 It is a schematic diagram of the cross-sectional structure of the steering box in the present invention; Figure 4 for Figure 3 A partial enlarged schematic diagram of the middle A area; Figure 5 It is a schematic diagram of the explosion structure of the second mounting frame in the present invention; Figure 6 It is a structural principle diagram of the resistance tester body of the present invention; Figure 7 A circuit diagram of a voltage signal conditioning circuit of the present invention; Figure 8 It is a circuit diagram of the voltage divider follower filter unit of the present invention.

[0019] In the figure: 1. Box body; 2. Buckle; 3. Protective cover; 4. Fixing block; 5. Carrying handle; 6. Mounting frame 1; 7. Cooling fan; 8. Adjustment box; 9. Mounting frame 2; 10. Filter; 11. Resistance tester body; 12. Ventilation hole; 13. Disassembly cylinder; 14. Bidirectional motor; 15. Turbine; 16. Worm; 17. Reversing blade; 18. L-shaped sliding rod; 19. Toggle block; 20. Transmission shaft; 21. Special-shaped disk; 22. Toggle frame; 23. Toggle rod; 24. Limit rod; 25. Insert rod; 26. Reset spring; 27. Turning handle. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0021] The present invention provides a technical solution: Figure 1 - Figure 5As shown, in the present embodiment, a portable AC / DC dual-purpose ground resistance tester comprises a box body 1, a cooling fan 7 is fixedly mounted on one side of the box body 1, a ventilation hole 12 is penetrated and opened on the other side of the box body 1, a direction adjustment box 8 is fixedly mounted on one side of the cooling fan 7, a toggle frame 22 is slidably connected to the inner bottom of the direction adjustment box 8, a special-shaped disk 21 is arranged above the toggle frame 22, an output end of the special-shaped disk 21 is slidably connected to the inner wall of the toggle frame 22, one end of the toggle frame 22 is rotatably connected to a toggle rod 23, the middle part of the toggle rod 23 is slidably connected to a limit rod 24, one end of the limit rod 24 is fixedly connected to one side of the inner wall of the direction adjustment box 8, one side of the toggle rod 23 is slidably connected to an L-shaped sliding rod 18, and the toggle rod 23 is rotatably connected to one side of the inner wall of the direction adjustment box 8 and near the edge. There are multiple reversing blades 17, and a toggle block 19 is fixedly connected to one side edge of the multiple reversing blades 17. One side of the multiple toggle blocks 19 is rotatably connected to the upper end of the L-shaped sliding rod 18. By turning on the bidirectional motor 14, the output end of the bidirectional motor 14 drives the cooling fan 7 and the worm 16 to rotate respectively, so that the output end of the special-shaped disk 21 drives the toggle frame 22 to slide in the adjustment box 8, and the toggle frame 22 swings the toggle rod 23 along the limit rod 24, and the L-shaped sliding rod 18 slides in the inner wall of the adjustment box 8. When sliding, the toggle block 19 pulls the L-shaped sliding rod 18 to rotate in the adjustment box 8, changing the flow direction of the cooling air of the cooling fan 7, thereby achieving dead-angle cooling of the electronic components on the resistance tester body 11 and improving the service life of the electronic components.

[0022] like Figure 3 As shown, a bidirectional motor 14 is fixedly installed at the input end of the cooling fan 7, and a worm 16 is transmission-connected to the output end of the bidirectional motor 14. A turbine 15 is meshed on one side of the worm 16, and a transmission shaft 20 is fixedly connected to the lower end of the turbine 15. One end of the transmission shaft 20 is fixedly connected to the middle part of the upper end of the special-shaped disk 21. The driving force of the bidirectional motor 14 is decelerated through the cooperation of the turbine 15 and the worm 16 to prevent the reversing blades 17 from rotating too fast and affecting the gas reversal.

[0023] like Figure 1 , Figure 3 and Figure 5 As shown, a mounting frame 2 9 is fixedly connected to the other side of the cooling fan 7, and a filter screen 10 is slidably connected to the inner wall of the mounting frame 9. The filter screen 10 can filter the gas entering the box body 1 to prevent dust from entering the box body 1 and affecting the operation of electronic components.

[0024] like Figure 3 and Figure 5As shown, a disassembly cylinder 13 is fixedly connected to one side of the mounting frame 29, and an insertion rod 25 is slidably connected to the inner wall of the disassembly cylinder 13. A return spring 26 is sleeved on one side of the outer wall of the insertion rod 25, and one end of the return spring 26 is fixedly connected to one side of the inner wall of the disassembly cylinder 13, and one end of the insertion rod 25 is rotatably connected to a rotating handle 27, and one side of the outer wall of the rotating handle 27 is rotatably connected to one side of the outer wall of the disassembly cylinder 13. By pulling the rotating handle 27, the insertion rod 25 slides from the filter screen 10 into the disassembly cylinder 13, releasing the restriction of the filter screen 10, and then the filter screen 10 is pulled out from the mounting frame 29, thereby realizing the cleaning and replacement of the filter screen 10 and preventing the filter holes in the filter screen 10 from becoming smaller due to long-term use, which affects the heat dissipation effect. Two disassembly cylinders 13 are installed on both sides of the mounting frame 29.

[0025] like Figure 1 As shown, a resistance tester body 11 is fixedly mounted on the inner wall of the box 1 .

[0026] like Figure 6 As shown, the resistance tester body includes a voltage sampling circuit, a signal preprocessing circuit, a processor module, a display module, an interface module, a reset module and a power module; the voltage sampling circuit is connected to the processor module through the signal preprocessing circuit, and the display module, the interface module, the reset module and the power module are respectively connected to the processor module. The voltage sampling circuit calculates the insulation resistance value through the processor module according to a predetermined algorithm using the collected voltage value.

[0027] The signal preprocessing circuit includes a voltage signal conditioning circuit, an analog switch unit, a voltage divider follower filter unit, and an A / D conversion unit. The voltage sampling circuit is connected to the controller module through the voltage signal conditioning circuit, the analog switch unit, the voltage divider follower filter unit, and the A / D conversion unit in sequence.

[0028] like Figure 7 As shown, the voltage signal conditioning circuit includes a voltage signal input terminal, a resistor R3, a resistor R4, a resistor R5, a capacitor C2, and an operational amplifier U2. The voltage signal input terminal is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to one end of the resistor R4 and one end of the resistor R5, the other end of the resistor R5 is connected to one end of the capacitor C2, the other end of the capacitor C2 is respectively connected to the other end of the resistor R4 and the positive input terminal of the operational amplifier U1, and the negative input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2.

[0029] In the voltage conditioning circuit, the rail-to-rail op amp can maximize the input and output voltage swings close to the power supply voltage value, but there is also a large deviation under high current conditions. Since the input voltage range of AD8608 is 0~0.5V, resistors R3 and R5 are set to form a voltage divider circuit to reduce the input voltage to below 5V.

[0030] like Figure 8 As shown, the voltage divider follower filter unit includes an operational amplifier U3, a resistor R11, a resistor R12, an operational amplifier U4, a resistor R13, and a capacitor C7. The output end of the operational amplifier U3 is connected to one end of the resistor R12, and the other end of the resistor R12 is respectively connected to one end of the resistor R11 and the positive input end of the operational amplifier U4. The output end of the operational amplifier U4 is connected to one end of the resistor R13, and the other end of the resistor R13 is respectively connected to one end of the capacitor C7 and the A / D conversion unit. The other end of the capacitor C7 is grounded, and the other end of the resistor R11 is connected to the current signal conditioning circuit.

[0031] The signal passes through the analog switch and then passes through the voltage divider % follower % filter circuit, and then is input into the AD converter. The voltage follower makes the circuit present high impedance input and low impedance output, improving the circuit's load capacity. The chip model of the operational amplifier U3 and the operational amplifier U4 is AD8031. The maximum sampling current of the ACS714 chip is 5A.

[0032] A protective cover 3 is rotatably connected to one side of the box body 1 near the edge, and the protective cover 3 can protect the test port on the resistance tester body 11 to prevent dust from entering.

[0033] like Figure 1 As shown, one side of the protective cover 3 is fixedly connected to a fixing block 4, and the other side of the box body 1 and near the edge is fixedly connected to a buckle 2, and the snap ring of the buckle 2 is snapped with the outer wall of the fixing block 4. Through the cooperation of the buckle 2 and the fixing block 4, the protective cover 3 is fixed to the box body 1 to prevent the protective cover 3 from falling off the box body 1 when carrying, thereby affecting the protective effect.

[0034] like Figure 1 As shown, a mounting frame 6 is fixedly connected to the middle of the other side of the box body 1, and a carrying handle 5 is rotatably connected to the inner wall of the mounting frame 6, through which the device can be conveniently picked up and carried.

[0035] The present invention provides a portable AC / DC dual-purpose ground resistance tester, the specific working principle of which is as follows: When using the resistance tester, the bidirectional motor 14 is turned on, and the output end of the bidirectional motor 14 drives the cooling fan 7 and the worm 16 to rotate respectively, so that the output end of the special-shaped disk 21 drives the toggle frame 22 to slide in the adjustment box 8, and the toggle frame 22 swings the toggle rod 23 along the limit rod 24, and the L-shaped sliding rod 18 slides in the inner wall of the adjustment box 8. When sliding, the toggle block 19 pulls the L-shaped sliding rod 18 to rotate in the adjustment box 8, changing the flow direction of the cooling wind of the cooling fan 7, and cooling the electronic components on the resistance tester body 11 without dead angles. When the equipment is used for a long time and the air intake effect of the filter 10 becomes worse, the rotating handle 27 is pulled, and the insertion rod 25 slides from the filter 10 to the disassembly cylinder 13, the restriction of the filter 10 is released, and then the filter 10 is pulled out from the mounting frame 29, so as to clean and replace the filter 10.

[0036] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A portable AC / DC dual-purpose ground resistance tester, comprising a box (1), characterized in that: A cooling fan (7) is fixedly mounted on one side of the box body (1), a ventilation hole (12) is penetrated through the other side of the box body (1), a direction adjustment box (8) is fixedly mounted on one side of the cooling fan (7), a toggle frame (22) is slidably connected to the inner bottom of the direction adjustment box (8), a special-shaped disk (21) is arranged above the toggle frame (22), an output end of the special-shaped disk (21) is slidably connected to the inner wall of the toggle frame (22), one end of the toggle frame (22) is rotatably connected to a toggle rod (23), and the toggle frame (22) is rotatably connected to the inner wall of the toggle frame (22). The middle part of the rod (23) is slidably connected to a limit rod (24), one end of the limit rod (24) is fixedly connected to one side of the inner wall of the steering box (8), one side of the toggle rod (23) is slidably connected to an L-shaped sliding rod (18), one side of the inner wall of the steering box (8) and close to the edge are rotatably connected to a plurality of reversing blades (17), one side edge of the plurality of reversing blades (17) is fixedly connected to a toggle block (19), one side of the plurality of reversing blades (17) is rotatably connected to the upper end of the L-shaped sliding rod (18).

2. A portable AC / DC ground resistance tester according to claim 1, characterized in that: A bidirectional motor (14) is fixedly mounted on the input end of the cooling fan (7), and a worm (16) is drivingly connected to the output end of the bidirectional motor (14). A turbine (15) is meshed on one side of the worm (16), and a transmission shaft (20) is fixedly connected to the lower end of the turbine (15). One end of the transmission shaft (20) is fixedly connected to the middle portion of the upper end of the special-shaped disk (21).

3. A portable AC / DC ground resistance tester according to claim 1, characterized in that: The other side of the cooling fan (7) is fixedly connected to a second mounting frame (9), and the inner wall of the second mounting frame (9) is slidably connected to a filter screen (10).

4. A portable AC / DC ground resistance tester according to claim 3, characterized in that: A disassembly cylinder (13) is fixedly connected to one side of the mounting frame (9), an insertion rod (25) is slidably connected to the inner wall of the disassembly cylinder (13), a return spring (26) is sleeved on one side of the outer wall of the insertion rod (25), one end of the return spring (26) is fixedly connected to one side of the inner wall of the disassembly cylinder (13), one end of the insertion rod (25) is rotatably connected to a rotating handle (27), and one side of the outer wall of the rotating handle (27) is rotatably connected to one side of the outer wall of the disassembly cylinder (13).

5. A portable AC / DC ground resistance tester according to claim 1, characterized in that: A resistance tester body (11) is fixedly mounted on the inner wall of the box (1), and the resistance tester body (11) comprises a voltage sampling circuit, a signal preprocessing circuit, a processor module, a display module, an interface module, a reset module and a power module; the voltage sampling circuit is connected to the processor module via the signal preprocessing circuit, and the display module, the interface module, the reset module and the power module are respectively connected to the processor module.

6. A portable AC / DC ground resistance tester according to claim 5, characterized in that: The signal preprocessing circuit includes a voltage signal conditioning circuit, an analog switch unit, a voltage divider follower filter unit, and an A / D conversion unit. The voltage sampling circuit is connected to the controller module through the voltage signal conditioning circuit, the analog switch unit, the voltage divider follower filter unit, and the A / D conversion unit in sequence.

7. A portable AC / DC ground resistance tester according to claim 6, characterized in that: The voltage signal conditioning circuit includes a voltage signal input terminal, a resistor R3, a resistor R4, a resistor R5, a capacitor C2, and an operational amplifier U2. The voltage signal input terminal is connected to one end of the resistor R3, the other end of the resistor R3 is respectively connected to one end of the resistor R4 and one end of the resistor R5, the other end of the resistor R5 is connected to one end of the capacitor C2, the other end of the capacitor C2 is respectively connected to the other end of the resistor R4 and the positive input terminal of the operational amplifier U1, and the negative input terminal of the operational amplifier U2 is connected to the output terminal of the operational amplifier U2.

8. A portable AC / DC ground resistance tester according to claim 6, characterized in that: The voltage divider follower filter unit includes an operational amplifier U3, a resistor R11, a resistor R12, an operational amplifier U4, a resistor R13, and a capacitor C7. The output end of the operational amplifier U3 is connected to one end of the resistor R12, and the other end of the resistor R12 is respectively connected to one end of the resistor R11 and the positive input end of the operational amplifier U4. The output end of the operational amplifier U4 is connected to one end of the resistor R13, and the other end of the resistor R13 is respectively connected to one end of the capacitor C7 and the A / D conversion unit. The other end of the capacitor C7 is grounded, and the other end of the resistor R11 is connected to the current signal conditioning circuit.

9. A portable AC / DC ground resistance tester according to claim 5, characterized in that: A protective cover (3) is rotatably connected to one side of the box body (1) near the edge, a fixing block (4) is fixedly connected to one side of the protective cover (3), and a buckle (2) is fixedly connected to the other side of the box body (1) near the edge, the buckle (2) having a buckle ring that is buckled with the outer side wall of the fixing block (4).

10. A portable AC / DC ground resistance tester according to claim 1, characterized in that: A mounting frame 1 (6) is fixedly connected to the middle of the other side of the box body (1), and a carrying handle (5) is rotatably connected to the inner wall of the mounting frame 1 (6).

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