CN211348429U - Ground resistance tester - Google Patents
Ground resistance tester Download PDFInfo
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- CN211348429U CN211348429U CN201922006787.3U CN201922006787U CN211348429U CN 211348429 U CN211348429 U CN 211348429U CN 201922006787 U CN201922006787 U CN 201922006787U CN 211348429 U CN211348429 U CN 211348429U
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Abstract
The utility model relates to a resistance test instrument field discloses a ground resistance tester, including frequency generator, current signal acquisition circuit, preamplification circuit, voltage signal acquisition circuit, amplifier, wave filter, ADC sampling circuit, singlechip, display module and wireless communication module, frequency generator's output respectively with current signal acquisition circuit's input with voltage signal acquisition circuit's input is connected, current signal acquisition circuit's output with preamplification circuit's input is connected, preamplification circuit's output with the input of wave filter is connected, voltage signal acquisition circuit's output with the input of amplifier is connected, the output of amplifier with the input of wave filter is connected. Implement the utility model discloses an earth resistance tester has following beneficial effect: the data transmission mode is more convenient and can reduce the data transmission cost.
Description
Technical Field
The utility model relates to a resistance test instrument field, in particular to ground resistance tester.
Background
The ground resistance tester is a novel digital ground resistance tester which abandons the traditional manual hand-operated power generation working mode, adopts an advanced large-scale integrated circuit and combines the three-terminal button and four-terminal button measuring modes into one model by applying a DC/AC conversion technology. The device is suitable for measuring the grounding resistance of various devices and the resistance value of a low-resistance conductor in departments of electric power, post and telecommunications, railways, communication, mines and the like, and can also be used for measuring the resistivity of soil and the ground voltage. However, in the conventional technology, when some ground resistance testers transmit the measured ground resistance to a remote end, the ground resistance is generally transmitted to a data transmitter, digital signals are transmitted to a data receiver by frequency band transmission after being encoded, and remote display can be realized under the control of a remote controller, so that the data transmission mode is complicated, and the data transmission cost is increased invisibly.
SUMMERY OF THE UTILITY MODEL
The to-be-solved technical problem of the utility model lies in that, to the above-mentioned defect of prior art, provide a ground resistance tester that data transmission mode is comparatively convenient, can reduce data transmission cost.
The utility model provides a technical scheme that its technical problem adopted is: a grounding resistance tester is constructed, and comprises a frequency generator, a current signal acquisition circuit, a pre-amplification circuit, a voltage signal acquisition circuit, an amplifier, a filter, an ADC (analog to digital converter) sampling circuit, a single chip microcomputer, a display module and a wireless communication module, wherein the output end of the frequency generator is respectively connected with the input end of the current signal acquisition circuit and the input end of the voltage signal acquisition circuit, the output end of the current signal acquisition circuit is connected with the input end of the pre-amplification circuit, the output end of the pre-amplification circuit is connected with the input end of the filter, the output end of the voltage signal acquisition circuit is connected with the input end of the amplifier, the output end of the amplifier is connected with the input end of the filter, the output end of the filter is connected with the input end of the ADC sampling circuit, and the output end of the ADC sampling circuit is connected with the input end of, the output end of the single chip microcomputer is connected with the display module, and the wireless communication module is connected with the single chip microcomputer.
Ground resistance tester in, wireless communication module is bluetooth module, wiFi module, GSM module, GPRS module, CDMA2000 module, WCDMA module, TD-SCDMA module, Zigbee module or loRa module.
In the ground resistance tester, the preamplifier circuit includes a sensor, a first diode, a second resistor, a first operational amplifier, a third resistor, a first power supply, a first capacitor, a first resistor, a second power supply, a fourth resistor, a fifth resistor, a second diode, a second operational amplifier and a voltage output terminal, a first pin of the sensor is connected with an anode of the first diode and one end of the second resistor, a second pin of the sensor and a cathode of the first diode are all grounded, the other end of the second resistor is connected with an inverting input terminal of the first operational amplifier and one end of the third resistor, a power supply terminal of the first operational amplifier is connected with the first power supply, a ground terminal of the first operational amplifier is grounded, an in-phase input terminal of the first operational amplifier is connected with one end of the first capacitor, One end of the first resistor is connected with the second power supply, and the other end of the first capacitor and the other end of the first resistor are both grounded;
the output end of the first operational amplifier is connected with the other end of the third resistor and the anode of the second diode respectively, the cathode of the second diode is connected with the non-inverting input end of the second operational amplifier, the inverting input end of the second operational amplifier is connected with one end of the fourth resistor and one end of the fifth resistor respectively, the other end of the fourth resistor is connected with the second power supply, the other end of the fifth resistor is grounded, the power supply end of the second operational amplifier is connected with the first power supply, the ground end of the second operational amplifier is grounded, and the output end of the second operational amplifier is connected with the voltage output end.
In the ground resistance tester of the present invention, the second diode has a model of S-701T.
In the ground resistance tester, the pre-amplification circuit further includes a sixth resistor, one end of the sixth resistor is connected to the non-inverting input terminal of the first operational amplifier, and the other end of the sixth resistor is connected to one end of the first capacitor.
In the ground resistance tester of the present invention, the resistance of the sixth resistor is 45k Ω.
In the ground resistance tester of the present invention, the first diode has a model of 1N 4148.
Ground resistance tester in, the first power is the 3.3V power, the second power is the 5V power.
Implement the utility model discloses an earth resistance tester has following beneficial effect: owing to be equipped with frequency generator, current signal acquisition circuit, preamplification circuit, voltage signal acquisition circuit, amplifier, wave filter, ADC sampling circuit, singlechip, display module and wireless communication module, can directly send measured ground resistance value for the display device of distal end to show through wireless communication module, consequently the utility model discloses data transmission mode is comparatively convenient, can reduce the data transmission cost.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
Fig. 1 is a schematic structural diagram of an embodiment of the ground resistance tester of the present invention;
fig. 2 is a circuit schematic of the preamplifier circuit in the embodiment.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.
In the embodiment of the ground resistance tester of the present invention, the schematic structural diagram of the ground resistance tester is shown in fig. 1. In fig. 1, the ground resistance tester comprises a frequency generator 1, a current signal acquisition circuit 2, a pre-amplification circuit 3, a voltage signal acquisition circuit 4, an amplifier 5, a filter 6, an ADC sampling circuit 7, a single chip microcomputer 8, a display module 9 and a wireless communication module 10, wherein an output end of the frequency generator 1 is connected with an input end of the current signal acquisition circuit 2 and an input end of the voltage signal acquisition circuit 4 respectively, an output end of the current signal acquisition circuit 2 is connected with an input end of the pre-amplification circuit 3, an output end of the pre-amplification circuit 3 is connected with an input end of the filter 6, an output end of the voltage signal acquisition circuit 4 is connected with an input end of the amplifier 5, an output end of the amplifier 5 is connected with an input end of the filter 6, an output end of the filter 6 is connected with an input end of the ADC sampling circuit 7, an output end of the ADC sampling circuit 7 is connected, the output end of the singlechip 8 is connected with the display module 9, and the wireless communication module 10 is connected with the singlechip 8.
This ground resistance tester is converted direct current signal into alternating current signal through frequency generator 1 and is tested, gathers the electric current and the voltage signal of auxiliary test utmost point under the control through singlechip 8, and the signal is through enlargiing, the filtering back, through ADC sampling circuit 7's sampling again, and the digital signal who will convert transmits and carries out the calculation processing in singlechip 8, just reachs the ground resistance value who tests, shows through display module 9. Meanwhile, the single chip microcomputer 8 directly sends the calculated grounding resistance value to the display device at the far end through the wireless communication module 10 to display, and the controller and the like of the data transmitter, the data receiver and the far end in the traditional technology are omitted, so that the utility model discloses data transmission mode is comparatively convenient, the data transmission cost can be reduced.
In this embodiment, the type adopted by the single chip microcomputer 8 is AT89S51, and the filter 6 is a band-pass filter, and is mainly used for removing interference of high-frequency components, low-frequency components and direct-current signals and ensuring the quality of current signals. The ADC sampling circuit 7 adopts a chip with the model of DAC 0832. And when the voltage and current signals are collected, the system is right. The ADC sampling circuit 7 is initialized, a sampling channel and a sampling point are set, a pulse counter is started at the same time, a sampling result is stored in an RAM memory of the single chip microcomputer 8, after a set number of sampling points is reached, the sampling process is finished, and data are transmitted to the single chip microcomputer 8 for calculation processing.
In this embodiment, the wireless communication module 10 is a bluetooth module, a WiFi module, a GSM module, a GPRS module, a CDMA2000 module, a WCDMA module, a TD-SCDMA module, a Zigbee module, or a LoRa module. Through setting up multiple wireless communication mode, not only can increase the flexibility of wireless communication mode, can also satisfy the demand of different users and different occasions. Especially, when adopting the loRa module, its communication distance is far away, and communication performance is comparatively stable, is applicable to the occasion that requires the communication quality to be higher.
In this embodiment, the frequency generator 1, the current signal acquisition circuit 2, the voltage signal acquisition circuit 4, the amplifier 5, the filter 6, the ADC sampling circuit 7, the single chip microcomputer 8, the display module 9, and the wireless communication module 10 are all implemented by using a structure in the prior art, and the working principle thereof is also a working principle in the prior art, which is not described herein.
Fig. 2 is a schematic circuit diagram of a preamplifier circuit in this embodiment, in fig. 2, the preamplifier circuit 3 includes a sensor P, a first diode D1, a second resistor R2, a first operational amplifier a1, a third resistor R3, a first power VCC, a first capacitor C1, a first resistor R1, a second power VDD, a fourth resistor R4, a fifth resistor R5, a second diode D2, a second operational amplifier a2, and a voltage output Vo, wherein the first pin of the sensor P is respectively connected to an anode of the first diode D1 and one end of the second resistor R2, the second pin of the sensor P and a cathode of the first diode D1 are both grounded, the other end of the second resistor R2 is respectively connected to an inverting input terminal of the first operational amplifier a1 and one end of the third resistor R3, a power terminal of the first operational amplifier a1 is connected to the first power VCC, a ground terminal of the first operational amplifier a1 is grounded, the non-inverting input terminal of the first operational amplifier a1 is connected to one terminal of the first capacitor C1, one terminal of the first resistor R1, and the second power supply VDD, and the other terminal of the first capacitor C1 and the other terminal of the first resistor R1 are both grounded.
The output end of the first operational amplifier a1 is connected to the other end of the third resistor R3 and the anode of the second diode D2, the cathode of the second diode D2 is connected to the non-inverting input end of the second operational amplifier a2, the inverting input end of the second operational amplifier a2 is connected to one end of the fourth resistor R4 and one end of the fifth resistor R5, the other end of the fourth resistor R4 is connected to the second power supply VDD, the other end of the fifth resistor R5 is grounded, the power supply end of the second operational amplifier a2 is connected to the first power supply VCC, the ground end of the second operational amplifier a2 is grounded, and the output end of the second operational amplifier a2 is connected to the voltage output Vo.
In this embodiment, the second diode D2 is a current limiting diode for current limiting protection. The current limiting protection principle is as follows: when the current of the branch where the second diode D2 is located is large, the current of the branch where the second diode D2 is located can be reduced by the second diode D2, so that the branch is kept in a normal operating state, and the components in the circuit are not burned out due to the large current, so that the safety and reliability of the circuit are high. It should be noted that in this embodiment, the second diode D2 has a model number S-701T. Of course, in practical applications, the second diode D2 may also be another type of diode with similar functions.
In this embodiment, the first diode D1 has a model number of 1N 4148. The first power source VCC is a 3.3V power source, and the second power source VDD is a 5V power source.
In this embodiment, the preamplifier circuit 3 further includes a sixth resistor R6, one end of the sixth resistor R6 is connected to the non-inverting input terminal of the first operational amplifier a1, and the other end of the sixth resistor R6 is connected to one end of the first capacitor C1. The sixth resistor R6 is a current limiting resistor for current limiting protection. The current limiting protection principle is as follows: when the current of the branch where the sixth resistor R6 is located is large, the magnitude of the current of the branch where the sixth resistor R6 is located can be reduced by the sixth resistor R6, so that the branch can be kept in a normal operating state, and the components in the circuit cannot be burned out due to the large current, so that the safety and reliability of the circuit are further enhanced. It should be noted that in the embodiment, the resistance value of the sixth resistor R6 is 45k Ω, and certainly, in practical applications, the resistance value of the sixth resistor R6 may be adjusted according to specific situations, that is, the resistance value of the sixth resistor R6 may be increased or decreased according to specific situations.
In a word, in this embodiment, owing to adopt wireless communication module 10, singlechip 8 directly sends the earth resistance value who calculates for the display device of distal end through wireless communication module 10 and shows, and it has saved the controller etc. of data sender, data receiver and distal end among the conventional art, consequently the utility model discloses data transmission mode is comparatively convenient, can reduce data transmission cost.
The above description is only a preferred embodiment of the present invention, and should not be taken as limiting the invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. A grounding resistance tester is characterized by comprising a frequency generator, a current signal acquisition circuit, a pre-amplification circuit, a voltage signal acquisition circuit, an amplifier, a filter, an ADC (analog to digital converter) sampling circuit, a single chip microcomputer, a display module and a wireless communication module, wherein the output end of the frequency generator is respectively connected with the input end of the current signal acquisition circuit and the input end of the voltage signal acquisition circuit, the output end of the current signal acquisition circuit is connected with the input end of the pre-amplification circuit, the output end of the pre-amplification circuit is connected with the input end of the filter, the output end of the voltage signal acquisition circuit is connected with the input end of the amplifier, the output end of the amplifier is connected with the input end of the filter, the output end of the filter is connected with the input end of the ADC sampling circuit, and the output end of the ADC sampling circuit is connected with the input end of the single chip microcomputer, the output end of the single chip microcomputer is connected with the display module, and the wireless communication module is connected with the single chip microcomputer.
2. The ground resistance tester of claim 1, wherein the wireless communication module is a bluetooth module, a WiFi module, a GSM module, a GPRS module, a CDMA2000 module, a WCDMA module, a TD-SCDMA module, a Zigbee module, or a LoRa module.
3. The ground resistance tester according to claim 1, wherein the preamplifier circuit comprises a sensor, a first diode, a second resistor, a first operational amplifier, a third resistor, a first power supply, a first capacitor, a first resistor, a second power supply, a fourth resistor, a fifth resistor, a second diode, a second operational amplifier and a voltage output terminal, a first pin of the sensor is connected with an anode of the first diode and one end of the second resistor, respectively, a second pin of the sensor and a cathode of the first diode are grounded, the other end of the second resistor is connected with an inverting input terminal of the first operational amplifier and one end of the third resistor, respectively, a power supply terminal of the first operational amplifier is connected with the first power supply, a ground terminal of the first operational amplifier is grounded, a non-inverting input terminal of the first operational amplifier is connected with one end of the first capacitor, respectively, One end of the first resistor is connected with the second power supply, and the other end of the first capacitor and the other end of the first resistor are both grounded;
the output end of the first operational amplifier is connected with the other end of the third resistor and the anode of the second diode respectively, the cathode of the second diode is connected with the non-inverting input end of the second operational amplifier, the inverting input end of the second operational amplifier is connected with one end of the fourth resistor and one end of the fifth resistor respectively, the other end of the fourth resistor is connected with the second power supply, the other end of the fifth resistor is grounded, the power supply end of the second operational amplifier is connected with the first power supply, the ground end of the second operational amplifier is grounded, and the output end of the second operational amplifier is connected with the voltage output end.
4. The ground resistance tester of claim 3, wherein the second diode is of type S-701T.
5. The ground resistance tester of claim 3, wherein the pre-amplifier circuit further comprises a sixth resistor, one end of the sixth resistor is connected to the non-inverting input of the first operational amplifier, and the other end of the sixth resistor is connected to one end of the first capacitor.
6. The ground resistance tester of claim 5, wherein the sixth resistor has a resistance of 45k Ω.
7. The earth resistance tester as claimed in any one of claims 3 to 6 wherein the first diode is of the type 1N 4148.
8. A ground resistance tester as claimed in any one of claims 3 to 6 wherein the first power supply is a 3.3V supply and the second power supply is a 5V supply.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922006787.3U CN211348429U (en) | 2019-11-19 | 2019-11-19 | Ground resistance tester |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922006787.3U CN211348429U (en) | 2019-11-19 | 2019-11-19 | Ground resistance tester |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211348429U true CN211348429U (en) | 2020-08-25 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201922006787.3U Active CN211348429U (en) | 2019-11-19 | 2019-11-19 | Ground resistance tester |
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|---|---|
| CN (1) | CN211348429U (en) |
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- 2019-11-19 CN CN201922006787.3U patent/CN211348429U/en active Active
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