CN215066974U

CN215066974U - Digital atmospheric electric field instrument based on FPGA

Info

Publication number: CN215066974U
Application number: CN202121031486.7U
Authority: CN
Inventors: 姬梓荣; 徐伟
Original assignee: Nanjing University of Information Science and Technology
Current assignee: Nanjing University of Information Science and Technology
Priority date: 2021-05-14
Filing date: 2021-05-14
Publication date: 2021-12-07
Anticipated expiration: 2031-05-14

Abstract

The utility model provides a digital atmospheric electric field appearance based on FPGA relates to meteorological detection technical field. The digital atmospheric electric field instrument comprises: the device comprises an electric field induction probe, a support bracket, a base and an FPGA processing box; the electric field induction probe is arranged above the supporting bracket, the base is arranged below the supporting bracket, the FPFA processing box is arranged on the supporting bracket, and the FPGA processing box is connected with the electric field induction probe; the FPGA processing box comprises: the device comprises an I/V conversion unit, a differential amplification unit, a low-pass filtering unit, a signal conditioning unit, an A/D acquisition unit, an FPGA and a display screen which are sequentially connected, wherein the differential amplification unit is connected with the A/D acquisition unit, and the I/V conversion unit is connected with an electric field induction probe. The utility model discloses a digital atmosphere electric field appearance facilitates for the signal processing of digital atmosphere electric field appearance through FPGA processing case, has simplified the circuit structure and the volume of atmosphere electric field appearance, has eliminated noise jamming through electric field signal processing module simultaneously.

Description

Digital atmospheric electric field instrument based on FPGA

Technical Field

The utility model relates to a meteorological detection technical field specifically relates to a digital atmosphere electric field appearance based on FPGA.

Background

The atmospheric electric field, which is a basic parameter of atmospheric electricity, exists between the earth surface and the high-altitude ionosphere and has important significance in the research on the atmospheric electric field, thunderstorms and lightning. The measurement of the atmospheric electric field intensity is indispensable to the aspects of researching the electrical structure of the cloud, the electrification theory, lightning protection and the like. The atmospheric electric field instrument is meteorological equipment which can be applied to the related fields of environmental monitoring, lightning early warning, electric field measurement and the like. The atmospheric electric field instrument is equipment for measuring an atmospheric electric field, can measure continuous changes of the strength and polarity of the atmospheric electric field under sunny days and thunderstorm weather conditions, can detect changes of a ground electric field caused by lightning discharge, and can continuously monitor the electrification process of a convection cloud. The atmospheric electric field instrument can record the electrical activity in thunderstorms before lightning occurs and can record the lightning generated in the thunderstorms. Therefore, the atmospheric electric field instrument is an important observation instrument for researching the time change characteristics of the atmospheric electric field and the cloud structure characteristics.

In the observation and research process of the atmospheric electric field, the most common method used by people is to measure by means of an atmospheric electric field instrument, a signal processing circuit of the traditional atmospheric electric field instrument is composed of a multi-stage analog signal processing circuit, the power consumption of a sensor is increased due to the multi-stage circuit structure, interference noise signals are transmitted stage by stage due to the series circuit structure, and meanwhile, common-mode interference between a moving plate and a fixed plate is difficult to eliminate in the measurement process of a preceding-stage induction probe. Although the patent with application number CN2015206387944 proposes the external structure of the atmospheric electric field instrument, the internal circuit structure of the atmospheric electric field instrument is not clear, and the measurement range of the atmospheric electric field instrument is not given.

SUMMERY OF THE UTILITY MODEL

To the problem that exists among the prior art, the utility model provides a digital atmosphere electric field appearance based on FPGA, this digital atmosphere electric field appearance facilitates for the signal processing of digital atmosphere electric field appearance through FPGA processing case, has simplified the circuit structure and the volume of atmosphere electric field appearance, has eliminated noise interference through electric field signal processing module simultaneously.

In order to achieve the above purpose, the utility model adopts the following technical scheme: a digital atmospheric electric field instrument based on FPGA comprises: the device comprises an electric field induction probe, a support bracket, a base and an FPGA processing box; the electric field induction probe is arranged above the supporting bracket, the base is arranged below the supporting bracket, the FPFA processing box is arranged on the supporting bracket, and the FPGA processing box is connected with the electric field induction probe; the FPGA processing box comprises: the device comprises an I/V conversion unit, a differential amplification unit, a low-pass filtering unit, a signal conditioning unit, an A/D acquisition unit, an FPGA and a display screen which are sequentially connected, wherein the differential amplification unit is connected with the A/D acquisition unit, and the I/V conversion unit is connected with an electric field induction probe.

Further, the I/V conversion unit comprises a first capacitor C1, a second capacitor C2, a first resistor R1, a second resistor R2, an AD8626 operational amplifier and a first power supply; the first resistor R1, the first capacitor C1 and the first amplifying circuit of the AD8626 operational amplifier are connected in parallel, the second resistor R2, the second capacitor C2 and the second amplifying circuit of the AD8626 operational amplifier are connected in parallel, the positive electrode of the first power supply is connected with the positive power end of the AD8626 operational amplifier, the negative electrode of the first power supply is connected with the negative power end of the AD8626 operational amplifier, and the output ends of the first amplifying circuit and the second amplifying circuit of the AD8626 operational amplifier are connected with the differential amplifier.

Further, the differential amplifying unit includes: AD620 operational amplifier, sliding rheostat R_gAnd a second power supply; the slide rheostat R_gIs connected with the first gain resistance port of the AD620 operational amplifier, and the slide rheostat R_gThe other end of the second power supply is connected with a second gain resistance port of the AD620 operational amplifier, a reference level port of the AD620 operational amplifier is connected with the A/D acquisition unit, the positive electrode of the second power supply is connected with the positive power supply end of the AD620 operational amplifier, the negative electrode of the second power supply is connected with the negative power supply end of the AD620 operational amplifier, and the output end of the AD620 operational amplifier is connected with the low-pass filtering unit.

Furthermore, the inverting input end of the AD620 operational amplifier is connected with the output end of the first amplifying circuit of the AD8626 operational amplifier in the I/V conversion unit, and the non-inverting input end of the AD620 operational amplifier is connected with the output end of the second amplifying circuit of the AD8626 operational amplifier in the I/V conversion unit.

Further, the low-pass filtering unit includes: the power supply comprises a third power supply, an LF353 operational amplifier, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5 and a sixth capacitor C6; one end of the third resistor R3 is connected to an output end of the AD620 operational amplifier, the other end of the third resistor R3 is connected to one end of the fourth resistor R4 and the negative electrode of the third capacitor C3, the same-direction input end of the first amplifying circuit of the LF353 operational amplifier is connected to the other end of the fourth resistor R4 and the positive electrode of the fourth capacitor C4, the negative electrode of the fourth capacitor C4 is grounded, the reverse input end of the first amplifying circuit of the LF353 operational amplifier is connected to one end of the fifth resistor R5 and one end of the sixth resistor R6, the other end of the fifth resistor R5 is grounded, the output end of the first amplifying circuit of the LF353 operational amplifier is connected to the positive electrode of the third capacitor C3, the other end of the sixth resistor R6 and one end of the seventh resistor R7, the other end of the seventh resistor R7 is connected to one end of the eighth resistor R8 and the negative electrode of the fifth capacitor C5, the same-direction input end of a second amplifying circuit of the LF353 operational amplifier is respectively connected with the anode of a sixth capacitor C6 and the other end of an eighth resistor R8, the cathode of the sixth capacitor is grounded, the reverse input end of the second amplifying circuit of the LF353 operational amplifier is respectively connected with one end of a ninth resistor R9 and one end of a tenth resistor R10, the other end of the ninth resistor R9 is grounded, and the output end of the second amplifying circuit of the LF353 operational amplifier is respectively connected with the anode of a fifth capacitor C5, the other end of the tenth resistor R10 and a signal conditioning unit; the positive electrode of the third power supply is connected with the positive power supply end of the LF353 operational amplifier, and the negative electrode of the third power supply is connected with the negative power supply end of the LF353 operational amplifier.

Further, the signal conditioning unit includes: the resistor comprises an LM324 operational amplifier, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9 and a tenth capacitor C10; one end of the seventh capacitor C7 is connected to an output end of the second amplifying circuit of the LF353 operational amplifier, the other end of the seventh capacitor C7 is connected to one end of an eleventh resistor R11, a same-direction input end of the LM324 operational amplifier is connected to one end of an eighth capacitor C8, one end of a twelfth resistor and the other end of an eleventh resistor R11, respectively, an output end of the LM324 operational amplifier is connected to the other end of an eighth capacitor C8, the other end of a twelfth resistor R12, one end of a thirteenth resistor R13 and the a/D acquisition unit, respectively, the other end of the thirteenth resistor R13 is grounded, an inverting input end of the LM324 operational amplifier is connected to one end of a fourteenth resistor R14, the other end of the fourteenth R14 is connected to one end of a ninth capacitor C9, one end of a tenth capacitor C10, one end of a sixteenth resistor R16 and one end of a fifteenth resistor R15, respectively, the other end of the ninth capacitor C9, the other end of the tenth capacitor C10 and the other end of the sixteenth resistor R16 are grounded, and the other end of the fifteenth resistor R15 is connected to a supply voltage.

Further, a positive power supply end of the LM324 operational amplifier is connected to a supply voltage, and a negative power supply end of the LM324 operational amplifier and the other end of the thirteenth resistor R13 are both grounded.

Further, the a/D acquisition unit includes: the circuit comprises a precise sampling chip ADS8326, a reference voltage source REF5025, an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, a fourteenth capacitor C14, a fifteenth capacitor C15, a fourth power supply and a fifth power supply; an IN + port of the precision sampling chip ADS8326 is connected with an output end of an LM324 operational amplifier IN the signal conditioning unit, a REF port and an IN-port of the precision sampling chip ADS8326 are respectively connected with one end of an eleventh capacitor C11, one end of a fifteenth capacitor C15 and a VOUT port of a reference voltage source REF5025, the other end of the eleventh capacitor C11 is grounded, the other end of the fifteenth capacitor is grounded, a VIN port of the reference voltage source REF5025 is respectively connected with one end of a fourteenth capacitor C14 and the positive pole of a fourth power supply, and a GND port of the reference voltage source REF5025 and the other end of the fourteenth capacitor C14 are both grounded; a VDD port of the precision sampling chip ADS8326 is connected to one end of a twelfth capacitor C12, one end of a thirteenth capacitor C13, and an anode of a fifth power supply, respectively, and the other end of the twelfth capacitor C12 and the other end of the thirteenth capacitor C13 are grounded.

Furthermore, a DCLOCK port of the precise sampling chip ADS8326 is connected with a CLK port of the FPGA, a DOUT port of the precise sampling chip ADS8326 is connected with an INPUT port of an AD/DA interface on the FPGA, a CS port of the precise sampling chip ADS8326 is connected with a CS port of the FPGA, and a REF port of the precise sampling chip ADS8326 is connected with a reference level port of the AD620 operational amplifier.

Furthermore, a VGA port of the FPGA is connected with a display screen.

Compared with the prior art, the utility model discloses following beneficial effect has: the utility model discloses an atmosphere electric field appearance passes through integrated circuit with I/V conversion unit, difference amplification unit, low pass filter unit, signal conditioning unit, AD acquisition unit, FPGA and display screen and installs in the FPGA treatment box, has reduced the connection of external circuit to the circuit structure and the volume of atmosphere electric field appearance have been simplified. The utility model eliminates the common mode interference in the electric field induction probe through the differential amplification unit, and improves the stability of signal transmission; the utility model further weakens the external signal interference through the low-pass filtering unit and the signal conditioning unit, and ensures the stable transmission of the voltage signal; the utility model discloses a voltage signal that FPGA exported AD acquisition element carries out amplitude measurement and polarity measurement to show on the display screen, improved the digital degree of this atmosphere electric field appearance. The utility model discloses a digital atmosphere electric field appearance has characteristics small, conveniently carry, that the precision is high.

Drawings

Fig. 1 is a schematic structural diagram of the digital atmospheric electric field instrument based on the FPGA of the present invention;

FIG. 2 is a schematic diagram of the unit connection in the FPGA processing box of the digital atmospheric electric field instrument based on FPGA of the present invention;

FIG. 3 is a schematic diagram of the circuit connection of the FPGA processing box in the FPGA-based digital atmospheric electric field instrument of the present invention;

the device comprises an electric field induction probe 1, a support bracket 2, a base 3 and an FPGA processing box 4.

Detailed Description

The technical solution of the present invention will be further explained with reference to the accompanying drawings.

As fig. 1 does the utility model discloses digital atmosphere electric field appearance based on FPGA, include: the device comprises an electric field induction probe 1, a support bracket 2, a base 3 and an FPGA processing box 4; electric field inductive probe 1 sets up in the top of support holder 2, and base 3 sets up in the below of support holder 2, and FPFA handles case 4 and sets up on support holder 2, and FPGA handles case 4 and is connected with electric field inductive probe 1. The utility model discloses expose the stator in electric field inductive probe 1 in turn at electric field or by the shielding of driven piece, will produce weak current signal on the stator, carry it to handle in FPGA handles case 4, finally show on the display screen. As fig. 2, the utility model discloses a case is handled to FPGA includes: the device comprises an I/V conversion unit, a differential amplification unit, a low-pass filtering unit, a signal conditioning unit, an A/D acquisition unit, an FPGA and a display screen which are sequentially connected, wherein the differential amplification unit is connected with the A/D acquisition unit, the I/V conversion unit is connected with an electric field induction probe 1, the electric field induction probe induces current signals in the atmosphere to obtain direct current voltage signals in proportion to the electric field intensity E after passing through the I/V conversion unit, the differential amplification unit and the low-pass filtering unit, the signal conditioning unit performs voltage translation on the signals to enable the signals to be in line with the input range of the A/D acquisition unit, and the A/D acquisition unit acquires the voltage signals output by the signal conditioning unit and performs discretization; and the digital signal processing of the electric field signal is realized through the FPGA, the accurate measurement of the atmospheric electric field strength and the judgment of the polarity of the electric field are completed, and finally the effective output of the digital electric field signal is realized.

If fig. 3 is the utility model discloses FPGA handles the circuit connection schematic diagram of case among the digital atmosphere electric field appearance based on FPGA, wherein, the utility model provides an IO conversion unit includes: a first capacitor C1 of 100 muF, a second capacitor C2 of 100 muF, a first resistor R1 of 10K Ω, a second resistor R2 of 10K Ω, an AD8626 operational amplifier and a first power supply of 5V; the first resistor R1, the first capacitor C1 and the first amplifying circuit of the AD8626 operational amplifier are connected in parallel, the second resistor R2, the second capacitor C2 and the second amplifying circuit of the AD8626 operational amplifier are connected in parallel, the positive electrode of the first power supply is connected with the positive power supply end of the AD8626 operational amplifier, the negative electrode of the first power supply is connected with the negative power supply end of the AD8626 operational amplifier, and the output ends of the first amplifying circuit and the second amplifying circuit of the AD8626 operational amplifier are connected with the differential amplifier. The AD8626 operational amplifier has the characteristics of low noise and rail-to-rail output, and because the first resistor R1 and the second resistor R2 are equal, and the first capacitor C1 and the second capacitor C2 are equal, at the same time, the signals at the output end of the first amplifying circuit of the AD8626 operational amplifier and the output end of the second amplifying circuit of the AD8626 operational amplifier are equal in magnitude and opposite in phase.

The utility model discloses well difference amplification unit includes: the AD620 operational amplifier, the sliding rheostat Rg of 4.94-49.4K omega and a second power supply of 5V; the utility model provides a AD620 operational amplifier is high accuracy, low-power consumption, rail to the instrument operational amplifier of rail output, only needs through changing external resistance Rg, alright realize the regulation of gain G that amplifies, and the G scope is 1~ 10000. The gain adjustment relationship is as follows:

thus, the slide rheostat R_gIs connected with the first gain resistor port of the AD620 operational amplifier, and a slide rheostat R_gThe other end and AD620 operational amplifier's second gain resistance port be connected, AD620 operational amplifier's reference level port is connected with AD acquisition unit, insert reference level, can realize the whole lifting to differential signal, with the input signal scope of matching AD acquisition unit, the positive pole of second power is connected with AD620 operational amplifier's positive power source end, the negative pole of second power is connected with AD620 operational amplifier's negative power source end, AD620 operational amplifier's output and low pass filter unit are connected, realize the differential amplification to the current signal of input, the utility model provides an AD620 operational amplifier can realize the differential amplification effect to 2 way signal for AD86 in AD620 operational amplifier's reverse input end and the I/V conversion unit is gone into to AD620 operational amplifier's negative input endThe output end of the first amplifying circuit of the 26 operational amplifier is connected, and the homodromous input end of the AD620 operational amplifier is connected with the output end of the second amplifying circuit of the AD8626 operational amplifier in the I/V conversion unit, so that the common-mode interference between the preceding stage induction chips in the electric field induction probe 1 is effectively eliminated, and the current signal precision is improved.

The utility model discloses well low pass filter unit adopts fourth order butterworth filter circuit, specifically includes: a third power supply of 5V, an LF353 operational amplifier, a third resistor R3 of 51K Ω, a fourth resistor R4 of 240K Ω, a fifth resistor R5 of 11K Ω, a sixth resistor R6 of 100K Ω, a seventh resistor R7 of 43K Ω, an eighth resistor R8 of 330K Ω, a ninth resistor R9 of 11K Ω, a tenth resistor R10 of 100K Ω, a third capacitor C3 of 100pF, a fourth capacitor C4 of 1nF, a fifth capacitor C5 of 100pF and a sixth capacitor C6 of 1 nF; one end of a third resistor R3 is connected with an output end of an AD620 operational amplifier, the other end of the third resistor R3 is respectively connected with one end of a fourth resistor R4 and the negative electrode of a third capacitor C3, the same-direction input end of a first amplifying circuit of the LF353 operational amplifier is respectively connected with the other end of the fourth resistor R4 and the positive electrode of a fourth capacitor C4, the negative electrode of a fourth capacitor C4 is grounded, the reverse direction input end of the first amplifying circuit of the 353 LF operational amplifier is respectively connected with one end of a fifth resistor R5 and one end of a sixth resistor R6, the other end of a fifth resistor R5 is grounded, the output end of the first amplifying circuit of the LF353 operational amplifier is respectively connected with the positive electrode of the third capacitor C3, the other end of a sixth resistor R6 and one end of a seventh resistor R7, the other end of a seventh resistor R7 is respectively connected with one end of an eighth resistor R8 and the negative electrode of a fifth capacitor C5, and the second amplifying circuit of the same-direction input end of the sixth capacitor C6, The other end of the eighth resistor R8 is connected, the negative electrode of the sixth capacitor is grounded, the inverting input end of the second amplifying circuit of the LF353 operational amplifier is respectively connected with one end of the ninth resistor R9 and one end of the tenth resistor R10, the other end of the ninth resistor R9 is grounded, and the output end of the second amplifying circuit of the LF353 operational amplifier is respectively connected with the positive electrode of the fifth capacitor C5, the other end of the tenth resistor R10 and the signal conditioning unit; the positive pole of the third power supply is connected with the positive power supply end of the LF353 operational amplifier, and the negative pole of the third power supply is connected with the negative power supply end of the LF353 operational amplifier. The utility model provides a LF353 operational amplifier has two enlargies, high impedance, low bias current's characteristic constitution fourth order active filter, and cutoff frequency f =10 Hz, and consequently, this low pass filter unit has kept useful low frequency signal, has carried out great decay to the noise.

The utility model discloses well signal conditioning unit includes: an LM324 operational amplifier, an eleventh resistor R11 of 100K Ω, a twelfth resistor R12 of 1M Ω, a thirteenth resistor R13 of 5.1K Ω, a fourteenth resistor R14 of 100K Ω, a fifteenth resistor R15 of 10K Ω, a sixteenth resistor R16 of 10K Ω, a seventh capacitor C7 of 1 μ F, an eighth capacitor C8 of 6800pF, a ninth capacitor C9 of 0.1 μ F, and a tenth capacitor C10 of 220 μ F; one end of a seventh capacitor C7 is connected to an output end of the second amplifying circuit of the LF353 operational amplifier, the other end of the seventh capacitor C7 is connected to one end of an eleventh resistor R11, a homodromous input end of the LM324 operational amplifier is connected to one end of an eighth capacitor C8, one end of a twelfth resistor and the other end of an eleventh resistor R11, an output end of the LM324 operational amplifier is connected to the other end of an eighth capacitor C8, the other end of a twelfth resistor R12, one end of a thirteenth resistor R13 and the a/D acquisition unit, the other end of the thirteenth resistor R13 is grounded, an inverting input end of the LM324 operational amplifier is connected to one end of a fourteenth resistor R14, the other end of the fourteenth R14 is connected to one end of a ninth capacitor C9, one end of a tenth capacitor C10, one end of a sixteenth resistor R16 and one end of a fifteenth resistor R15, the other end of a ninth capacitor C9 and the other end of a tenth capacitor C10, The other end of the sixteenth resistor R16 is grounded, the other end of the fifteenth resistor R15 is connected with the power supply voltage, the positive power supply end of the LM324 operational amplifier is connected with the power supply voltage, and the negative power supply end of the LM324 operational amplifier and the other end of the thirteenth resistor R13 are both grounded. The utility model discloses direct current and extremely low frequency interference can be got rid of to well signal conditioning unit to restrain high frequency interference, carry out preliminary decay to the noise, enlarged useful signal simultaneously.

The utility model discloses well AD acquisition unit includes: the precise sampling chip ADS8326, the reference voltage source REF5025, the eleventh capacitor C11 of 10 muF, the twelfth capacitor C12 of 0.1 muF, the thirteenth capacitor C13 of 10 muF, the fourteenth capacitor C14 of 10nF, the fifteenth capacitor C15 of 10nF, the fourth power supply of 5V and the fifth power supply of 5V; an IN + port of the precision sampling chip ADS8326 is connected with an output end of an LM324 operational amplifier IN the signal conditioning unit, a REF port and an IN-port of the precision sampling chip ADS8326 are respectively connected with one end of an eleventh capacitor C11, one end of a fifteenth capacitor C15 and a VOUT port of a reference voltage source REF5025, the other end of the eleventh capacitor C11 is grounded, the other end of the fifteenth capacitor is grounded, a VIN port of the reference voltage source REF5025 is respectively connected with one end of a fourteenth capacitor C14 and the positive electrode of a fourth power supply, and a GND port of the reference voltage source REF5025 and the other end of the fourteenth capacitor C14 are both grounded; a VDD port of the precision sampling chip ADS8326 is connected to one end of a twelfth capacitor C12, one end of a thirteenth capacitor C13, and the anode of the fifth power supply, respectively, and the other end of the twelfth capacitor C12 and the other end of the thirteenth capacitor C13 are grounded; the REF end of the precise sampling chip ADS8326 is connected with the reference level port of the differential amplification unit, the DCLOCK port of the precise sampling chip ADS8326 is connected with the CLK port of the FPGA, so that the FPGA provides a clock signal for the precise sampling chip AD8326, the DOUT port of the precise sampling chip ADS8326 is connected with the INPUT port of the AD/DA interface on the FPGA, the discretization signal output by the A/D acquisition unit is processed by the FPGA to obtain a precise atmosphere electric field intensity signal and electric field polarity, the VGA port of the FPGA is connected with the display screen for digital output. And the CS port of the precise sampling chip ADS8326 is connected with the CS port of the FPGA, so that the FPGA provides a low-level effective chip selection signal for the A/D acquisition unit. The precise sampling chip ADS8326 used by the A/D acquisition unit is a 16-bit high-speed SAR (successive approximation type) A/D chip, and the data output rate can reach 250 kHz.

The utility model discloses digital atmosphere electric field appearance based on FPGA is small, simple structure, can realize the accurate of atmospheric electric field intensity signal and electric field polarity simultaneously and measure, can not receive the environmental factor influence, at the all-weather work that carries on in different time, different places, gathers the atmospheric electric field information that the staff needs. The lightning early warning system is wide in application field in real life, and can provide lightning early warning service for the meteorological industry; helping forestry departments to make thunder and lightning fire prevention early warning; and technical guarantee is provided for the power supply safety of the power department.

Above only the utility model discloses an it is preferred embodiment, the utility model discloses a scope of protection not only limits in above-mentioned embodiment, and the all belongs to the utility model discloses a technical scheme under the thinking all belongs to the utility model discloses a scope of protection. It should be noted that, for those skilled in the art, a plurality of modifications and decorations without departing from the principle of the present invention should be considered as the protection scope of the present invention.

Claims

1. The utility model provides a digital atmosphere electric field appearance based on FPGA which characterized in that includes: the device comprises an electric field induction probe (1), a support bracket (2), a base (3) and an FPGA processing box (4); the electric field induction probe (1) is arranged above the supporting bracket (2), the base (3) is arranged below the supporting bracket (2), the FPFA processing box (4) is arranged on the supporting bracket (2), and the FPGA processing box (4) is connected with the electric field induction probe (1); the FPGA processing box comprises: the device comprises an I/V conversion unit, a differential amplification unit, a low-pass filtering unit, a signal conditioning unit, an A/D acquisition unit, an FPGA and a display screen which are sequentially connected, wherein the differential amplification unit is connected with the A/D acquisition unit, and the I/V conversion unit is connected with an electric field induction probe (1).

2. The FPGA-based digital atmospheric electric field instrument according to claim 1, wherein the I/V conversion unit comprises: a first capacitor C1, a second capacitor C2, a first resistor R1, a second resistor R2, an AD8626 operational amplifier and a first power supply; the first resistor R1, the first capacitor C1 and the first amplifying circuit of the AD8626 operational amplifier are connected in parallel, the second resistor R2, the second capacitor C2 and the second amplifying circuit of the AD8626 operational amplifier are connected in parallel, the positive electrode of the first power supply is connected with the positive power end of the AD8626 operational amplifier, the negative electrode of the first power supply is connected with the negative power end of the AD8626 operational amplifier, and the output ends of the first amplifying circuit and the second amplifying circuit of the AD8626 operational amplifier are connected with the differential amplifier.

3. The FPGA-based digital atmospheric electric field instrument according to claim 1, wherein the differential amplification unit comprises: AD620 operational amplifier, sliding rheostat R_gAnd a second power supply; the slide rheostat R_gIs connected with the first gain resistance port of the AD620 operational amplifier, and the slide rheostat R_gThe other end of the second power supply is connected with a second gain resistance port of the AD620 operational amplifier, a reference level port of the AD620 operational amplifier is connected with the A/D acquisition unit, the positive electrode of the second power supply is connected with the positive power supply end of the AD620 operational amplifier, the negative electrode of the second power supply is connected with the negative power supply end of the AD620 operational amplifier, and the output end of the AD620 operational amplifier is connected with the low-pass filtering unit.

4. The FPGA-based digital atmospheric electric field instrument according to claim 3, wherein an inverting input terminal of the AD620 operational amplifier is connected to an output terminal of a first amplifying circuit of the AD8626 operational amplifier in the I/V converting unit, and a non-inverting input terminal of the AD620 operational amplifier is connected to an output terminal of a second amplifying circuit of the AD8626 operational amplifier in the I/V converting unit.

5. The FPGA-based digital atmospheric electric field instrument according to claim 1, wherein the low-pass filtering unit comprises: the power supply comprises a third power supply, an LF353 operational amplifier, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5 and a sixth capacitor C6; one end of the third resistor R3 is connected to an output end of the AD620 operational amplifier, the other end of the third resistor R3 is connected to one end of the fourth resistor R4 and the negative electrode of the third capacitor C3, the same-direction input end of the first amplifying circuit of the LF353 operational amplifier is connected to the other end of the fourth resistor R4 and the positive electrode of the fourth capacitor C4, the negative electrode of the fourth capacitor C4 is grounded, the reverse input end of the first amplifying circuit of the LF353 operational amplifier is connected to one end of the fifth resistor R5 and one end of the sixth resistor R6, the other end of the fifth resistor R5 is grounded, the output end of the first amplifying circuit of the LF353 operational amplifier is connected to the positive electrode of the third capacitor C3, the other end of the sixth resistor R6 and one end of the seventh resistor R7, the other end of the seventh resistor R7 is connected to one end of the eighth resistor R8 and the negative electrode of the fifth capacitor C5, the same-direction input end of a second amplifying circuit of the LF353 operational amplifier is respectively connected with the anode of a sixth capacitor C6 and the other end of an eighth resistor R8, the cathode of the sixth capacitor is grounded, the reverse input end of the second amplifying circuit of the LF353 operational amplifier is respectively connected with one end of a ninth resistor R9 and one end of a tenth resistor R10, the other end of the ninth resistor R9 is grounded, and the output end of the second amplifying circuit of the LF353 operational amplifier is respectively connected with the anode of a fifth capacitor C5, the other end of the tenth resistor R10 and a signal conditioning unit; the positive electrode of the third power supply is connected with the positive power supply end of the LF353 operational amplifier, and the negative electrode of the third power supply is connected with the negative power supply end of the LF353 operational amplifier.

6. The FPGA-based digital atmospheric electric field instrument of claim 1, wherein the signal conditioning unit comprises: the resistor comprises an LM324 operational amplifier, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventh capacitor C7, an eighth capacitor C8, a ninth capacitor C9 and a tenth capacitor C10; one end of the seventh capacitor C7 is connected to an output end of the second amplifying circuit of the LF353 operational amplifier, the other end of the seventh capacitor C7 is connected to one end of an eleventh resistor R11, a same-direction input end of the LM324 operational amplifier is connected to one end of an eighth capacitor C8, one end of a twelfth resistor and the other end of an eleventh resistor R11, an output end of the LM324 operational amplifier is connected to the other end of an eighth capacitor C8, the other end of a twelfth resistor R12, one end of a thirteenth resistor R13 and the a/D acquisition unit, the other end of the thirteenth resistor R13 is grounded, an inverting input end of the LM324 operational amplifier is connected to one end of a fourteenth resistor R14, the other end of the fourteenth R14 is connected to one end of a ninth capacitor C9, one end of a tenth capacitor C10, one end of a sixteenth resistor R16 and one end of a fifteenth resistor R15, the other end of the ninth capacitor C9, the other end of the tenth capacitor C10 and the other end of the sixteenth resistor R16 are grounded, and the other end of the fifteenth resistor R15 is connected to a supply voltage.

7. The FPGA-based digital atmospheric electric field instrument according to claim 6, wherein a positive power supply terminal of the LM324 operational amplifier is connected to a power supply voltage, and a negative power supply terminal of the LM324 operational amplifier and the other end of the thirteenth resistor R13 are grounded.

8. The FPGA-based digital atmospheric electric field instrument according to claim 1, wherein the A/D acquisition unit comprises: the circuit comprises a precise sampling chip ADS8326, a reference voltage source REF5025, an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, a fourteenth capacitor C14, a fifteenth capacitor C15, a fourth power supply and a fifth power supply; an IN + port of the precision sampling chip ADS8326 is connected with an output end of an LM324 operational amplifier IN the signal conditioning unit, a REF port and an IN-port of the precision sampling chip ADS8326 are respectively connected with one end of an eleventh capacitor C11, one end of a fifteenth capacitor C15 and a VOUT port of a reference voltage source REF5025, the other end of the eleventh capacitor C11 is grounded, the other end of the fifteenth capacitor is grounded, a VIN port of the reference voltage source REF5025 is respectively connected with one end of a fourteenth capacitor C14 and the positive pole of a fourth power supply, and a GND port of the reference voltage source REF5025 and the other end of the fourteenth capacitor C14 are both grounded; a VDD port of the precision sampling chip ADS8326 is connected to one end of a twelfth capacitor C12, one end of a thirteenth capacitor C13, and an anode of a fifth power supply, respectively, and the other end of the twelfth capacitor C12 and the other end of the thirteenth capacitor C13 are grounded.

9. The FPGA-based digital atmospheric electric field instrument of claim 8, wherein the DCLOCK port of the precision sampling chip ADS8326 is connected to the CLK port of the FPGA, the DOUT port of the precision sampling chip ADS8326 is connected to the INPUT port of the AD/DA interface on the FPGA, the CS port of the precision sampling chip ADS8326 is connected to the CS port of the FPGA, and the REF port of the precision sampling chip ADS8326 is connected to the reference level port of the AD620 operational amplifier.

10. The FPGA-based digital atmospheric electric field instrument according to claim 1, wherein the VGA port of the FPGA is connected with a display screen.