CN111025034A - Underwater electric field signal active detection circuit and detection method - Google Patents
Underwater electric field signal active detection circuit and detection method Download PDFInfo
- Publication number
- CN111025034A CN111025034A CN201911181613.9A CN201911181613A CN111025034A CN 111025034 A CN111025034 A CN 111025034A CN 201911181613 A CN201911181613 A CN 201911181613A CN 111025034 A CN111025034 A CN 111025034A
- Authority
- CN
- China
- Prior art keywords
- signal
- electric field
- electrode
- resistor
- dipole
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/12—Measuring electrostatic fields or voltage-potential
Abstract
The invention discloses an active detection circuit and a detection method for an underwater electric field signal, belongs to the technical field of underwater electric field signal detection, and can avoid zero drift and offset voltage in a differential amplification circuit in passive electric field measurement from interfering with a low-frequency electric field signal. The detection circuit comprises an alternating current excitation source, a dipole electrode, a current limiting resistor R6, a direct current isolation capacitor C4, a grounding resistor R7, a detector, an integrator and a filter. The frequency of the alternating current excitation source is more than 20 times of the signal frequency of the underwater electric field to be detected; the alternating current excitation source is connected to the signal input end of the dipole electrode, and the signal output end of the dipole electrode is connected with the detector through the direct current isolation capacitor C4; the dipole electrodes are located underwater. Two ends of the direct current isolation capacitor C4 are grounded through a current limiting resistor R6 and a grounding resistor R7 respectively. The rear end of the detector is connected with the integrator and the filter in sequence. And a signal at the output end of the integrator is fed back to the signal input end of the dipole motor.
Description
Technical Field
The invention relates to the technical field of underwater electric field signal detection, in particular to an underwater electric field signal active detection circuit and a detection method.
Background
Currently, in underwater electric field measurement, the potential difference between two points in an axial direction of an underwater electric field space is actually measured. Usually, a passive measurement mode is adopted, as shown in fig. 2, a conventional passive underwater electric field signal detection circuit is adopted, wherein an electric field sensor adopts Ag/AgCl electrodes or high-molecular polymer electrodes to form a dipole electrode array, a dipole motor comprises a first electrode and a second electrode, front circuits are respectively connected to the rear stages of 2 electrodes of the dipole electrode to convert current signals into voltage signals, and after the potential voltage acquired by the dipole electrode is processed by a differential amplifier, the potential difference between two points in a space electric field is obtained, so as to receive electric field signals. When the method needs to measure the underwater electric field signal of the target ship with the extremely low frequency of less than 0.2Hz, the inherent zero drift, the direct current bias voltage and the like of the differential amplification circuit form an extremely low frequency interference signal, and the test result is influenced.
In the underwater electric field measurement process, when an extremely low-frequency target ship underwater electric field signal needs to be measured, zero drift, direct-current bias voltage and the like of the differential amplification circuit form an extremely low-frequency interference signal, and a test result is influenced.
Therefore, a scheme capable of actively detecting an underwater electric field signal is needed, and interference of zero drift and offset voltage in a differential amplification circuit on a low-frequency electric field signal in passive electric field measurement can be avoided.
Disclosure of Invention
In view of this, the invention provides an underwater electric field signal active detection circuit and a detection method, which can avoid interference of zero drift and offset voltage in a differential amplification circuit on a low-frequency electric field signal in passive electric field measurement.
In order to achieve the purpose, the technical scheme of the invention is as follows: an active detection circuit for underwater electric field signals is used for detecting the amplitude of electric field signals of underwater electric field signals to be detected and comprises an alternating current excitation source, a dipole electrode, a current limiting resistor R6, a direct current isolation capacitor C4, a grounding resistor R7, a detector, an integrator and a filter.
The frequency of the alternating current excitation source is more than 20 times of the signal frequency of the underwater electric field to be detected;
the alternating current excitation source is connected to the signal input end of the dipole electrode, and the signal output end of the dipole electrode is connected with the detector through the direct current isolation capacitor C4; the dipole electrodes are located underwater.
Two ends of the direct current isolation capacitor C4 are grounded through a current limiting resistor R6 and a grounding resistor R7 respectively.
The rear end of the detector is connected with the integrator and the filter in sequence.
And a signal at the output end of the integrator is fed back to the signal input end of the dipole motor.
In the embodiment of the present invention, further, the dipole electrode includes 2 electrodes, which are respectively marked as a first electrode and a second electrode, the ac excitation source is connected to one end of the first electrode and one end of the second electrode, that is, the signal input end of the dipole motor, and the other end of the first electrode and the other end of the second electrode, that is, the signal output end of the dipole motor, is connected to the detector through the dc isolation capacitor C4.
In the embodiment of the invention, further, the alternating current excitation source consists of an oscillating circuit and an integrated inverter U3E;
the output end of the oscillation circuit outputs a normal phase alternating current excitation signal to be connected to the first electrode, and the signal frequency of the alternating current excitation signal is more than 20 times of that of the underwater electric field signal to be detected;
the output end of the oscillating circuit is connected with the input end of the integrated phase inverter U3E, and an inverse cross current excitation signal is obtained and connected to the second electrode.
In the embodiment of the present invention, the oscillation circuit is further composed of an operational amplifier U1A, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a second capacitor C2, and an eighth capacitor C8.
The second resistor R2 and the second capacitor C2 are connected in parallel, one end of the parallel circuit of R2 and C2 is connected with the pin 3 of the forward input end of the operational amplifier U1A, and the other end is grounded.
The third resistor R3 is connected in series with the eighth capacitor C8, and the series circuit of R3 and C8 is connected with the forward input pin 3 of the operational amplifier U1A at one end and the output pin 1 of U1A at the other end to form a feedback network.
The fourth resistor R4 has one end connected to pin 2 of the inverting input terminal of U1A and the other end connected to ground.
The fifth resistor R5 has one end connected to the inverted input pin 2 of U1A and one end connected to the output pin 1, forming another feedback network.
The embodiment of the invention also provides an active detection method of the underwater electric field signal, which adopts the circuit to detect the amplitude of the electric field signal of the underwater electric field signal to be detected and comprises the following steps:
the alternating current excitation source outputs an alternating current excitation signal with the frequency more than 20 times of the frequency of the underwater electric field signal to be detected.
The alternating current excitation signal is applied to 2 electrodes of the dipole electrode, a reference alternating electric field is generated between the 2 electrodes of the dipole motor and the seawater medium by the alternating current excitation signal, and the reference alternating electric field is superposed with the underwater electric field signal to be detected and modulated by the electric field signal to be detected to form an alternating modulation signal.
After the alternating modulation signal passes through the direct current isolation capacitor C4 and the grounding resistor R7, zero drift is isolated and the alternating modulation signal enters a detector.
After the alternating modulation signal passes through the detector, the superposed amplitude modulation information is restored and demodulated.
The amplitude modulation information outputs a direct current voltage amplitude signal of the underwater electric field signal through the integrator, and the direct current voltage amplitude signal is fed back to the signal input end of the dipole electrode and is used for compensating the attenuation of the underwater electric field signal to be detected in the circuit transmission process.
And the direct current voltage amplitude signal enters a filter to filter alternating current noise and output an amplitude detection signal of the underwater electric field signal to be detected.
Has the advantages that:
the invention is realized by adopting an active measurement method: an alternating current excitation source with a certain frequency is applied to the dipole electrodes, the excitation frequency is far higher than the signal frequency of the electric field to be detected (the excitation frequency is more than 20 times of the signal frequency to be detected), a reference alternating electric field is formed between the electrodes, when a target ship enters a water area to be detected, an underwater low-frequency electric field signal is superposed with a reference alternating surface electric field to form a modulation signal with amplitude change on the alternating electric field, and after the amplitude modulation signal is subjected to detection, integral summation and filtering processing, the amplitude information of the electric field signal to be detected is demodulated and restored. The amplitude information of the underwater electric field signal obtained by the detection circuit and the monitoring method provided by the invention can avoid the interference of zero drift and offset voltage in the differential amplification circuit on the low-frequency electric field signal in the passive electric field measurement.
Drawings
FIG. 1 is a schematic diagram of an active underwater electric field signal detection circuit provided by the present invention;
FIG. 2 is a schematic diagram of a conventional passive underwater electric field measurement circuit;
FIG. 3 is a dipole electric field equivalent diagram;
fig. 4 is a schematic diagram of a detailed circuit of the active detection circuit provided by the present invention.
Detailed Description
The invention is described in detail below by way of example with reference to the accompanying drawings.
The invention provides an underwater electric field signal active detection circuit, which is used for carrying out electric field signal amplitude detection on an underwater electric field signal to be detected and comprises an alternating current excitation source, a dipole electrode, a current-limiting resistor R6, a direct current isolation capacitor C4, a grounding resistor R7, a wave detector, an integrator and a filter, wherein the alternating current excitation source is connected with the dipole electrode;
the frequency of the alternating current excitation source is more than 20 times of the signal frequency of the underwater electric field to be measured.
The alternating current excitation source is connected to the signal input end of the dipole electrode, and the signal output end of the dipole electrode is connected with the detector through the direct current isolation capacitor C4; the dipole electrode is located in seawater.
In the embodiment of the invention, the dipole electrode comprises 2 electrodes which are respectively marked as a first electrode and a second electrode, an alternating current excitation source is connected to one end of the first electrode and one end of the second electrode, namely a signal input end of the dipole motor, and the other end of the first electrode and the other end of the second electrode, namely a signal output end of the dipole motor, are connected with the detector through a direct current isolation capacitor C4.
In the active measurement process, the seawater medium between the dipole electrode and the electrode is used as a load under the action of an excitation source to form an alternating electric field, and the equivalent circuit of the alternating electric field is shown in fig. 3:
the resistance Rg and the resistance R' g are contact resistances between the electrodes and the seawater conducting medium and are related to the material, the size and the like of the electrodes; and Rl and Cl are respectively the resistance and the capacitance of the seawater medium between the electrodes and are related to the conductivity of the seawater medium, the distance between the electrodes, the working frequency and the like.
Two ends of the direct current isolation capacitor C4 are grounded through a current limiting resistor R6 and a grounding resistor R7 respectively.
The rear end of the detector is connected with the integrator and the filter in sequence.
And a signal at the output end of the integrator is fed back to the signal input end of the dipole motor.
In the embodiment of the present invention, the ac excitation source is composed of an oscillation circuit and an integrated inverter U3E, as shown in fig. 4.
The output end of the oscillation circuit outputs a positive phase alternating current excitation signal to be connected to the first electrode, and the signal frequency of the alternating current excitation signal is more than 20 times of that of the underwater electric field signal to be detected.
As shown in fig. 4, the oscillation circuit includes an operational amplifier U1A, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a second capacitor C2, and an eighth capacitor C8.
The second resistor R2 and the second capacitor C2 are connected in parallel, one end of the parallel circuit of R2 and C2 is connected with the pin 3 of the forward input end of the operational amplifier U1A, and the other end is grounded.
The third resistor R3 is connected in series with the eighth capacitor C8, and the series circuit of R3 and C8 is connected with the forward input pin 3 of the operational amplifier U1A at one end and the output pin 1 of U1A at the other end to form a feedback network.
The fourth resistor R4 has one end connected to pin 2 of the inverting input terminal of U1A and the other end connected to ground.
The fifth resistor R5 has one end connected to the inverted input pin 2 of U1A and one end connected to the output pin 1, forming another feedback network.
Wherein, the numerical values are R2 ═ R3 ═ R, C2 ═ C8 ═ C, and R5 ═ 2R 4. The resonant frequency f of the excitation source oscillator is 1/2 pi RC; the value of the resonance frequency f is more than 20 times of the frequency of the electric field signal to be detected, which is beneficial to filtering the alternating current interference after demodulation.
The output end of the oscillating circuit is connected with the input end of the integrated phase inverter U3E, and an inverse cross current excitation signal is obtained and connected to the second electrode.
The embodiment of the invention also provides an active detection method of the underwater electric field signal, which adopts the detection circuit provided by the embodiment to detect the amplitude of the electric field signal of the underwater electric field signal to be detected, and comprises the following steps:
1) the AC excitation source outputs an AC excitation signal with the frequency more than 20 times of the frequency of the underwater electric field signal to be detected;
2) the AC excitation signal is applied to 2 electrodes of the dipole electrode, a reference alternating electric field is generated between the 2 electrodes of the dipole motor and the seawater medium by the AC excitation signal, the reference alternating electric field is superposed with the underwater electric field signal to be measured and is modulated by the electric field signal to be measured to form an alternating modulation signal
3) After the alternating modulation signal passes through a direct-current isolation capacitor C4 and a grounding resistor R7, zero drift is isolated and the alternating modulation signal enters a detector;
4) the detector diode D1 and the capacitor C6 form a forward detector, the detector diode D2 and the capacitor C5 form a reverse detector, and the bidirectional detector detects the peak value of the modulated alternating signal, and adds the detected signal to the current-limiting resistor R8 and R9 to input the detected signal to the subsequent stage.
After the alternating modulation signal passes through the detector, superposed amplitude modulation information is restored and demodulated;
5) the amplitude modulation information passes through an integrator, an operational amplifier U2A, a resistor R10 and a capacitor C7 form the integrator: one end of the resistor R10 is connected with the front stage, and the other end is connected with the reverse input end pin 2 of the operational amplifier; the capacitor C7 has one end connected to the inverted input terminal pin 2 of the operational amplifier U2A and one end connected to the output terminal pin 1 of the operational amplifier U2A.
The integrator outputs a direct-current voltage amplitude signal of the underwater electric field signal, and the direct-current voltage amplitude signal is fed back to a signal input end of the dipole electrode and is used for compensating the attenuation of the underwater electric field signal to be detected in the circuit transmission process;
6) and the direct current voltage amplitude signal enters a filter to filter alternating current noise and output an amplitude detection signal of the underwater electric field signal to be detected.
The filter is an RC filter and is composed of a resistor Rl1 and a capacitor Cl2, and the low-pass cut-off frequency of the filter is as follows:
f＝1/2πR11C12
after low-pass filtering, the alternating current noise on the electric field voltage amplitude signal is further filtered and output to a later stage.
In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (5)
1. An active detection circuit for underwater electric field signals is characterized by being used for detecting the amplitude of electric field signals of underwater electric field signals to be detected, and comprising an alternating current excitation source, dipole electrodes, a current limiting resistor R6, a direct current isolation capacitor C4, a grounding resistor R7, a detector, an integrator and a filter;
the frequency of the alternating current excitation source is more than 20 times of the signal frequency of the underwater electric field to be detected;
the alternating current excitation source is connected to the signal input end of the dipole electrode, and the signal output end of the dipole electrode is connected with the detector through a direct current isolation capacitor C4; the dipole electrodes are located underwater;
two ends of the direct current isolation capacitor C4 are grounded through the current limiting resistor R6 and the grounding resistor R7 respectively;
the rear end of the detector is sequentially connected with the integrator and the filter;
and a signal at the output end of the integrator is fed back to the signal input end of the dipole motor.
2. The circuit of claim 1, wherein the dipole electrode comprises 2 electrodes, which are respectively referred to as a first electrode and a second electrode, the ac excitation source is connected to one end of the first electrode and the second electrode, i.e. the signal input end of the dipole motor, and the other end of the first electrode and the second electrode, i.e. the signal output end of the dipole motor, is connected to the detector through a dc isolation capacitor C4.
3. The circuit of claim 2, wherein the ac excitation source is comprised of an oscillator circuit and an integrated inverter U3E;
the output end of the oscillation circuit outputs a normal phase alternating current excitation signal to be connected to the first electrode, and the signal frequency of the alternating current excitation signal is more than 20 times of that of the underwater electric field signal to be detected;
the output end of the oscillating circuit is connected with the input end of the integrated phase inverter U3E to obtain an anti-intersection flow excitation signal which is connected to the second electrode.
4. The circuit of claim 3, wherein the oscillation circuit is formed by an operational amplifier U1A, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a second capacitor C2, and an eighth capacitor C8;
the second resistor R2 and the second capacitor C2 are connected in parallel, one end of a parallel circuit of R2 and C2 is connected with a pin 3 of a positive input end of the operational amplifier U1A, and the other end of the parallel circuit is grounded;
the third resistor R3 is connected in series with the eighth capacitor C8, one end of a series circuit of R3 and C8 is connected with a forward input end pin 3 of the operational amplifier U1A, and the other end is connected with an output pin 1 of the U1A, so that a feedback network is formed;
one end of the fourth resistor R4 is connected with the inverted input end pin 2 of the U1A, and the other end is grounded;
the fifth resistor R5 has one end connected to the inverted input pin 2 of U1A and one end connected to the output pin 1, forming another feedback network.
5. An active detection method for underwater electric field signals, which is characterized in that the circuit of claim 1 is adopted to detect the amplitude of the electric field signals of the underwater electric field signals to be detected, and the method comprises the following steps:
the alternating current excitation source outputs an alternating current excitation signal with the frequency more than 20 times of the frequency of the underwater electric field signal to be detected;
the alternating current excitation signal is applied to 2 electrodes of the dipole electrode, a reference alternating electric field is generated between the 2 electrodes of the dipole electrode and a seawater medium by the alternating current excitation signal, and the reference alternating electric field is superposed with an underwater electric field signal to be detected and modulated by the electric field signal to be detected to form an alternating modulation signal;
after the alternating modulation signal passes through a direct-current isolation capacitor C4 and a grounding resistor R7, zero drift is isolated and the alternating modulation signal enters the detector;
after the alternating modulation signal passes through the detector, superposed amplitude modulation information is restored and demodulated;
the amplitude modulation information outputs a direct current voltage amplitude signal of the underwater electric field signal through the integrator, and the direct current voltage amplitude signal is fed back to the signal input end of the dipole electrode and is used for compensating the attenuation of the underwater electric field signal to be detected in the circuit transmission process;
and the direct current voltage amplitude signal enters the filter, alternating current noise is filtered, and an amplitude detection signal of the underwater electric field signal to be detected is output.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911181613.9A CN111025034B (en) | 2019-11-27 | 2019-11-27 | Underwater electric field signal active detection circuit and detection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911181613.9A CN111025034B (en) | 2019-11-27 | 2019-11-27 | Underwater electric field signal active detection circuit and detection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111025034A true CN111025034A (en) | 2020-04-17 |
| CN111025034B CN111025034B (en) | 2021-11-02 |
Family
ID=70202647
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911181613.9A Active CN111025034B (en) | 2019-11-27 | 2019-11-27 | Underwater electric field signal active detection circuit and detection method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111025034B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112838843A (en) * | 2020-12-30 | 2021-05-25 | 北京千方科技股份有限公司 | Signal conditioning device and signal conditioning method |
Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4370616A (en) * | 1980-08-15 | 1983-01-25 | Williams Bruce T | Low impedance electrostatic detector |
| US4814695A (en) * | 1983-03-04 | 1989-03-21 | Troesch Jacques J | Measurement method for an electrical signal, series-parallel negative-feedback measuring circuit, as well as use of the method of the measuring circuit for measuring voltage sources with very-high-ohmage internal impedances |
| CN1461518A (en) * | 2000-10-16 | 2003-12-10 | 鲁道夫·施瓦脱 | Method and device for detecting and processing signal waves |
| CN1607393A (en) * | 2003-10-15 | 2005-04-20 | 财团法人工业技术研究院 | Electromagnetic field sensing element and its apparatus |
| CN1768272A (en) * | 2003-03-28 | 2006-05-03 | 佳能株式会社 | Electric potential measuring device using oscillating device, image forming apparatus, and electric potential measuring method |
| US20060235635A1 (en) * | 2003-08-12 | 2006-10-19 | Nathan Intrator | Apparatus and method for performing the delay estimation of signals propagating through an environment |
| CN101576590A (en) * | 2009-04-03 | 2009-11-11 | 中国人民解放军理工大学 | Miniature electric field measuring apparatus |
| JP2011102762A (en) * | 2009-11-11 | 2011-05-26 | Technical Research & Development Institute Ministry Of Defence | Underwater electric field measuring device and underwater electric field measuring method |
| CN102694509A (en) * | 2011-03-22 | 2012-09-26 | 北京汉朔科技有限公司 | An integrated electro-physiological signal amplifier with an AC excitation function |
| CN103023581A (en) * | 2012-12-14 | 2013-04-03 | 陈曦鸣 | Grounding two-way digital information communication device utilizing ground electric field detection technology |
| CN105763268A (en) * | 2016-04-18 | 2016-07-13 | 国网新疆电力公司阿勒泰供电公司 | Underwater electric field communication device |
| CN106841831A (en) * | 2016-12-29 | 2017-06-13 | 成都冠禹科技有限公司 | A kind of electrostatic field tester |
| CN107329001A (en) * | 2017-05-25 | 2017-11-07 | 北京中科飞龙传感技术有限责任公司 | Alive circuit monitoring alarm device is closed on based on MEMS electric-field sensors |
| CN109752765A (en) * | 2018-12-14 | 2019-05-14 | 中国船舶重工集团公司第七一0研究所 | A kind of electric field signal reception system for ground mine |
-
2019
- 2019-11-27 CN CN201911181613.9A patent/CN111025034B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4370616A (en) * | 1980-08-15 | 1983-01-25 | Williams Bruce T | Low impedance electrostatic detector |
| US4814695A (en) * | 1983-03-04 | 1989-03-21 | Troesch Jacques J | Measurement method for an electrical signal, series-parallel negative-feedback measuring circuit, as well as use of the method of the measuring circuit for measuring voltage sources with very-high-ohmage internal impedances |
| CN1461518A (en) * | 2000-10-16 | 2003-12-10 | 鲁道夫·施瓦脱 | Method and device for detecting and processing signal waves |
| CN1768272A (en) * | 2003-03-28 | 2006-05-03 | 佳能株式会社 | Electric potential measuring device using oscillating device, image forming apparatus, and electric potential measuring method |
| US20060235635A1 (en) * | 2003-08-12 | 2006-10-19 | Nathan Intrator | Apparatus and method for performing the delay estimation of signals propagating through an environment |
| CN1607393A (en) * | 2003-10-15 | 2005-04-20 | 财团法人工业技术研究院 | Electromagnetic field sensing element and its apparatus |
| CN101576590A (en) * | 2009-04-03 | 2009-11-11 | 中国人民解放军理工大学 | Miniature electric field measuring apparatus |
| JP2011102762A (en) * | 2009-11-11 | 2011-05-26 | Technical Research & Development Institute Ministry Of Defence | Underwater electric field measuring device and underwater electric field measuring method |
| CN102694509A (en) * | 2011-03-22 | 2012-09-26 | 北京汉朔科技有限公司 | An integrated electro-physiological signal amplifier with an AC excitation function |
| CN103023581A (en) * | 2012-12-14 | 2013-04-03 | 陈曦鸣 | Grounding two-way digital information communication device utilizing ground electric field detection technology |
| CN105763268A (en) * | 2016-04-18 | 2016-07-13 | 国网新疆电力公司阿勒泰供电公司 | Underwater electric field communication device |
| CN106841831A (en) * | 2016-12-29 | 2017-06-13 | 成都冠禹科技有限公司 | A kind of electrostatic field tester |
| CN107329001A (en) * | 2017-05-25 | 2017-11-07 | 北京中科飞龙传感技术有限责任公司 | Alive circuit monitoring alarm device is closed on based on MEMS electric-field sensors |
| CN109752765A (en) * | 2018-12-14 | 2019-05-14 | 中国船舶重工集团公司第七一0研究所 | A kind of electric field signal reception system for ground mine |
Non-Patent Citations (2)
| Title |
|---|
| RONNIE ROSS 等: "Underwater electric field measurement and analysis", 《OCEANS 2017 - ANCHORAGE》 * |
| 郑舟 等: "水下电场测量系统的设计与实现", 《电子世界》 * |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112838843A (en) * | 2020-12-30 | 2021-05-25 | 北京千方科技股份有限公司 | Signal conditioning device and signal conditioning method |
| CN112838843B (en) * | 2020-12-30 | 2024-02-27 | 北京千方科技股份有限公司 | Signal conditioning device and signal conditioning method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111025034B (en) | 2021-11-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4713205B2 (en) | Capacitive sensor and method for non-contact measurement of gaps and dielectric media | |
| JP3448058B2 (en) | Magnetic flowmeter with empty pipe detector | |
| US8353210B2 (en) | System for measuring a physical variable | |
| US9551738B2 (en) | Robust capacitive measurement system | |
| US7518443B2 (en) | Amplifier circuit and method for reducing voltage and current noise | |
| CN111025034B (en) | Underwater electric field signal active detection circuit and detection method | |
| US5172065A (en) | Evaluation circuit for a capacitive sensor | |
| CN206099914U (en) | Lock -in amplifier | |
| US9112455B2 (en) | Signal amplifying circuit for electromagnetic flow meter | |
| EP0944817B1 (en) | Method and apparatus for electronic compensation of erroneous readings caused by resonance in a capacitive pressure transducer | |
| CN112050964A (en) | Temperature detection circuit, temperature monitoring method and electric automobile | |
| US7684938B1 (en) | Self-cleaning ultrasonic flow sensor | |
| CA2390176A1 (en) | Method and apparatus for testing a capacitive sensor | |
| CN106059510A (en) | Method and device for eliminating direct current drift output by capacitance coupling amplification circuit | |
| CN103592061B (en) | High precision silicon micro resonant pressure transducer interface circuit | |
| CN203203605U (en) | Weak-signal detection apparatus | |
| US10649015B1 (en) | Capacitive sensor including compensation for phase shift | |
| Mustapha et al. | Single supply differential capacitive sensor with parasitic capacitance and resistance consideration | |
| CN216792309U (en) | Isolation circuit and current detection circuit applying same | |
| CN217587395U (en) | Empty pipe detection circuit and measurement circuit of flowmeter | |
| CN215452889U (en) | High-precision digital demodulation circuit of eddy current sensor | |
| CN212514554U (en) | Quality of water sample collection system | |
| CN218301360U (en) | Signal amplification circuit for gas detector and gas detector | |
| CN212391143U (en) | Temperature detection circuit and electric automobile | |
| CN219627896U (en) | Capacitance sensor alternating current polarization circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |